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Related glossaries are  Informatics Overview, and Technologies: Assays, Labels, Signaling & Detection,  Mass Spectrometry,  Microarrays. NMR & X-ray crystallography.

2-photon: See two photon excitation. 

3-photon: See three photon excitation

anisotrophy: See under Near-field Scanning Optical Microscopy NSOM

atomic force microscopy AFM: A powerful tool for studying the size and range of small forces with high spatial resolution. Traditionally, AFM has been used to record the surface topography of a sample by recording the vertical motion of the probe tip as it is scanned over a sample. With a customized probe tip, however, specific interactions between the tip and the sample surface can be measured. In this type of experiment, molecular groups that interact with the sample are added to the tip so that separating the tip from the sample deflects the cantilever- tip assembly. ...  Manipulations with AFM in these studies have provided information about the structural basis for flexibility in proteins that have unusual elastic properties. In addition to making mechanical measurements, AFM has been used to observe the activity of individual proteins by measuring changes in protein positions over time. The development of carbon nanotubes for use as AFM tips is another promising approach to increasing the resolution of the method.  [NIGMS  Single Molecule Detection and Manipulation Workshop "Single Molecule Fluorescence of Biomolecules and Complexes Protein Folding April 17-18, 2000] http://www.nigms.nih.gov/news/reports/single_molecules.html#examples 

A type of scanning probe microscopy in which a probe systematically rides across the surface of a sample being scanned in a raster pattern. The vertical  position is recorded as a spring attached to the probe rises and falls in response to peaks and  valleys on the surface. These deflections produce a topographic map of the sample. [MeSH]

biophotonic imaging: A novel approach to functional genomics, target validation, and drug screening and preclinical testing. Uses a bioluminescent reporter gene to tag a target of interest - which can be a gene, a cell, or a microorganism - in a whole mouse. Because light passes through tissue, the labeled mouse can be anesthetized and photographed with a camera capable of detecting the bioluminescence. This method can be used to label bacteria, infect an organism, and study the effect of antibiotics on the infection, or the effects of various physiological conditions or drugs that can modify response to infection. In oncology, this approach can be used to label tumor cells and follow the effects of chemotherapeutic treatments on the cancer. One can do assays both in cell culture and in whole animals with a gene tagged with the same reporter, and one can follow changes in gene expression in real time both in cell culture and in whole animals. [CHI Target Validation]

biphotonic excitation: Also called two-photon excitation. The simultaneous (coherent) absorption of two photons (either same or different wavelength) the energy of excitation being the sum of the energies of the two photons. [IUPAC Photo]

CAT scan: See computed tomography

CCD Charged Coupled Device: Charge- coupled- device (CCD)- based fluorescence imagers are being developed in an attempt to provide more flexibility and to reduce cost. Rather than using a separate laser for each dye, CCD imagers use an arc lamp that has different filters to produce different excitation wavelengths. The CCD detectors are hampered by limitations in the computer chips that acquire the image from the camera and allow the image to be stored digitally. Further developments will be required for these devices’ performance to equal that of the confocal instruments. [CHI Microarray] 

Solid-state imaging chips which are produced using highly complex manufacturing methods. CCD's have been used since the 1970's for electronic imaging. CCD's consume relatively large amounts of power. [CRI, Inc. US,  Photon University Glossary]  http://www.cri-inc.com/photon/glossary.shtml

CCD camera: A CCD is a charge-coupled device – a silicon chip whose surface is divided into light- sensitive pixels. When a photon (light particle) hits a pixel, it registers a tiny electric charge that can be counted. With large pixel arrays and high sensitivity, CCDs can create high- resolution images under a variety of light conditions. A CCD camera incorporates a CCD to take such pictures. [Xenogen website, Glossary] http://www.xenogen.com/glossary.html 

CMOS: Short for "Complementary Metal- Oxide Semiconductor". When used in relation to electronic imaging, CMOS chips are solid- state chips which can be produced using less- expensive, industry- standard, manufacturing methods. Many people believe that CMOS imaging chips have the potential to become more popular than CCD's, because they use less power and can be manufactured with greater ease and more less money. CMOS imaging chips can also be designed with supplementary circuitry incorporated onto a single assembly, rather than many separate chips as is the case with CCD's. CMOS chips currently suffer some drawbacks, compared with CCD's, such as higher noise levels and lower total pixel counts.  [CRI, Inc. US,  Photon University Glossary]   http://www.cri-inc.com/photon/glossary.shtml

camera pill: Clinical genomics glossary

circular dichroism spectroscopy: The phenomenon of circular dichroism is very sensitive to the secondary structure of polypeptides and proteins . Circular dichroism (CD) spectroscopy is a form of light absorption spectroscopy that measures the difference in absorbance of right- and left- circularly polarized light (rather than the commonly used absorbance of isotropic light) by a substance. It has been shown that CD spectra between 260 and approximately 180 nm can be analyzed for the different secondary structural types: alpha helix, parallel and antiparallel beta sheet, turn, and other. [Kurt D. Berndt, Karolinska Institute, Sweden, Div. Molecular Biology, "Protein Secondary Structure" July 1996] http://broccoli.mfn.ki.se/pps_course_96/ss_960723_21.html

confocal microscopy: A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point- by- point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations  are possible. [MeSH] 

Used for fluorescence detection. Related term scanning technology.

Confocal Scanning Laser Scanning Microscopy CLSM: See under laser scanning microscopy

contrast agents: See imaging contrast agents.

cryofield emission scanning electron microscopy:

detector instrumentation:: Includes CCD cameras, lasers. See Assays, labels, signaling & detection glossary for detection technologies.

Einstein: One mole of photons. Although widely used, it is not an IUPAC sanctioned unit. It is sometimes defined as the energy of one mole of photons. This use is discouraged. [IUPAC Photo]

electron microscopy: Visual and photographic microscopy in which electron beams with wavelengths thousands of times shorter than visible light are used in place of light, thereby allowing much greater magnification.  [MeSH]

In high-resolution electron microscopy one can begin to do ``crystallography without crystals'', averaging thousands of images of single molecules or other assemblies to reveal near atomic level structure. These methods demand intense computing hardware, software and algorithm development. [Opportunities in Molecular Biomedicine in the Era of  Teraflop Computing:  March 3 & 4, 1999, Rockville, MD,  NIH Resource for Macromolecular Modeling and Bioinformatics;  Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana- Champaign] http://www.ks.uiuc.edu/Publications/Reports/teraflop/node4.html  Narrower term transmission electron microscopy (TEM).

Electron Microscopy Yellow Pages, Centre Interdepartmental de Microscopie Electronique, Ecole Polytechnique Federale de Lausanne http://cimewww.epfl.ch/EMYP/emyp.html

enhancement agents: See imaging contrast agents.

epifluorescence: An optical set- up for a fluorescence microscope in which the objective lens is used both to focus ultraviolet light on the specimen and collect fluorescent light from the specimen. Epifluorescence is more efficient than transmitted fluorescence, in which a separate lens or condenser is used to focus ultraviolet light on the specimen. Epifluorescence also allows fluorescence microscopy to be combined with another type on the same [Fluorescence Microscopy, HowStuffWorks.com, 2001] microscope. http://www.howstuffworks.com/light-microscope4.htm

evanescent wave: See under Total Internal Reflectance Fluorescence Microscopy

excitation: Narrower terms biphotonic excitation, three photon, two photon

FISH Fluorescence In Situ Hybridization: Gene Amplification & PCR glossary

FLIM Fluorescence Lifetime Imaging Microscopy: a technique in which the mean fluorescence lifetime of a chromophore is measured at each spatially resolvable element of a microscope image. The nanosecond excited-state lifetime is independent of probe concentration or light path length but dependent upon excited-state reactions such as fluorescence resonance energy transfer (FRET). These properties of fluorescence lifetimes allow exploration of the molecular environment of labelled macromolecules in the interior of cells. Imaging of fluorescence lifetimes enables biochemical reactions to be followed at each microscopically resolvable location within the cell.  a technique in which the mean fluorescence lifetime of a chromophore is measured at each spatially resolvable element of a microscope image. The nanosecond excited-state lifetime is independent of probe concentration or light path length but dependent upon excited-state reactions such as fluorescence resonance energy transfer (FRET). These properties of fluorescence lifetimes allow exploration of the molecular environment of labelled macromolecules in the interior of cells. Imaging of fluorescence lifetimes enables biochemical reactions to be followed at each microscopically resolvable location within the cell.  [Bastiaens, P.I. & Squire, A. Trends in Cell Biology Feb.1999 9 (2) : 48- 52 http://www-db.embl-heidelberg.de:4321/emblGroups/g_lits_126.html

 fiber optics, optical fibre: <communications> (fibre optics, FO, US "fiber", light pipe) A plastic or glass (silicon dioxide) fibre no thicker than a   human hair used to transmit information using infra- red or even visible light as the carrier (usually a laser). The light beam is an electromagnetic signal with a frequency in the range of 10^14 to 10^15 Hertz.

Optical fibre is less susceptible to external noise than other transmission media, and is cheaper to make than copper wire, but it is much more difficult to connect. Optical fibres are difficult to tamper with (to monitor or inject data in the middle of a connection), making them appropriate for secure communications. The light beams do not escape from the medium because the material used provides total internal reflection. [FOLDOC] 

Fluorescence Correlation Spectroscopy: See under Photon Correlation Spectroscopy.

fluorescence microscopy: Microscopy of specimens stained with fluorescent dye (usually fluorescein  isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye. [MeSH]  Narrower terms Laser Fluorescence Microscopy LFM, multi- photon excitation fluorescence microscopy,  Total Internal Reflectance Fluorescence Microscopy TIR-FM

fluorescence scanners: Microarrays glossary

fluorescence spectrometry: Measurement of the intensity and quality of fluorescence. [MeSH]

fluorescence spectroscopy- single molecule: Laser induced fluorescence allows the detection of single molecules in solids, in solution, and on surfaces. [Katrin Kneipp, "Single Molecule Spectroscopy" MIT, Spring 2001 course] http://ourworld.compuserve.com/Homepages/KatrinKneipp/topic6.htm

Fourier Transform Infrared Spectroscopy: A spectroscopic technique in which a range of wavelengths is presented simultaneously with an interferometer and the spectrum is mathematically derived from the pattern thus obtained. [MeSH]

functional imaging: As we gain a better understanding of the fundamental nature of cancer, cellular and molecular imaging will be a key tool in translating this knowledge into better ways of diagnosing, treating, and preventing the disease. Imaging can identify the kinds of molecular structures/ receptors that cover the surface of a tumor, information that potentially can predict how it may behave and respond to certain treatments. Or, by providing a picture of glucose utilization in tumor cells, imaging can demonstrate – without the need for a biopsy – how a tumor is responding to a recently administered treatment.  And seeing how the processes and pathways inside a cell change as the cell transforms from normal to cancerous will allow us to detect this change in people earlier in the cancer process, perhaps before a tumor has even had the chance to become fully malignant. Eventually we expect to be able to visualize the actual molecular signatures of a cancer. ... The potential of imaging to improve cancer treatment extends well beyond using imaging information to help select effective treatments or preventives.... In principle, imaging techniques can be interfaced with other tumor- killing approaches – toxic chemicals, gene therapy, heat, and cold – to more precisely guide tissue destruction at the tumor site. Being able to distinguish between cancerous and normal tissue and deliver treatments only to diseased tissues in a minimally invasive way will potentially minimize surgical trauma, shorten recovery time, and reduce health costs. [National Cancer Institute, US "Scientific Priorities for Cancer Research: NCI's Extraordinary Opportunities: Cancer Imaging" March 2000]  http://2001.cancer.gov/imaging.htm  Related terms Cell biology glossary, Functional genomics glossary

functional/metabolic imaging: LDRR [Laboratory of Diagnostic Radiology Research] has made significant technical advances in the areas of Functional/Metabolic Imaging. Advancement has been made in new proton multislice magnetic resonance spectroscopic imaging (MRSI) methods for evaluating the metabolites in the brain with similar resolution as found with PET. Studies from the Proton MRSI data can now be performed in as little as 10 minutes, which should also allow these techniques to be used for evaluating normal and abnormal cerebral metabolism. LDRR continues to be at the forefront of developing and evaluating new techniques for Functional MRI of the brain and other organs. Fast T2* sensitive 2-dimensional and 3-dimensional MR imaging techniques, with or without contrast agents, provide imaging researchers with the ability to unravel the mysteries of organ and cellular perfusion and for mapping cerebral function. The ability to obtain information on this time scale with improved spatial resolution was heretofore insurmountable with non-invasive technologies. These new techniques are being used in combination with for examining organ function and. Quantitative determinations of blood flow and oxygen consumption are actively being pursued using multinuclear MR imaging. The ability of functional/ metabolic imaging studies to monitor pharmacological alterations may provide the basis for future testing of new drugs for the treatment of malignancy, renal artery stenosis, heart disease, Alzheimer disease, cerebrovascular diseases, multiple sclerosis, AIDS and others. [NIH Clinical Center, Laboratory of Diagnostic Radiology Research, Initiatives, 2001]  http://www.cc.nih.gov/ldrr/htmlpg/Initiatives.html

image analysis, microarrays: Microarrays glossary

image cytometry: A technique encompassing morphometry, densitometry, neural networks, and expert systems that has numerous clinical and research applications and is particularly useful in anatomic pathology for the study of malignant lesions. The most common current application of image cytometry is for DNA analysis, followed by quantitation of immunohistochemical staining. [MeSH]  

is the measurement of cells from images. In our particular use it is the measurement of various attributes of cells from microscope images using fluorescence microscopy and computer image analysis techniques. Using image analysis cell populations can be distinguished and enumerated and cell sizes can be measured, as well as cell characteristics such as morphology and fluorescence color and intensity. [J. J. MacIsaac Facility for Individual Particle Analysis,  Bigelow Laboratory for Ocean Sciences, West Boothbay Harbor, ME, US] http://www.bigelow.org/cytometry/gen_info.html#What%20is%20imaging%20cytometry?

imaging (photoimaging): The use of a photosensitive system for the capture, recording, and retrieval of information associated with an object using electromagnetic energy. [IUPAC Photo] Narrower terms: biophotonic imaging, functional imaging, imaging - data mining, imaging contrast agents, imaging outcomes measurement, in vivo imaging, Magnetic Resonance Imaging MRI, quantitating imaging data, receptor imaging, spectral imaging Related terms image analysis - microarrays, image cytometry

imaging contrast agents: Developments in image enhancement agents are improving our ability to capture changes in the biochemical makeup of cells and other living structures. Enhancement agents contribute to image formation in three ways. They may localize in certain body organs or structures (anatomic localization); they may attach to specific molecules in the body (receptor localization); or they may become activated by certain biochemical or physical conditions, such as the presence of a specific enzyme or low oxygen concentration in the cell (activatable agents). We anticipate that contrast agents of the future will be able to reveal the functional characteristics of tumors that determine clinical behavior and response to therapy.  [National Cancer Institute, US "Scientific Priorities for Cancer Research: NCI's Extraordinary Opportunities: Cancer Imaging" March 2000]  http://2001.cancer.gov/imaging.htm 

imaging data mining: Data mining in brain imaging is proving to be an effective methodology for disease prognosis and prevention. This, together with the rapid accumulation of massive heterogeneous data sets, motivates the need for efficient methods that filter, clarify, assess, correlate and cluster brain- related information. Here, we present data mining methods that have been or could be employed in the analysis of brain images. These methods address two types of brain imaging data: structural and functional. We introduce statistical methods that aid the discovery of interesting associations and patterns between brain images and other clinical data. [Megalooikonomou V, Ford J, Shen L, Makedon F, Saykin A. "Data mining in brain imaging" Stat Methods Med Res 2000 Aug; 9 (4): 359-94 ] 

imaging outcomes measurement: Although it seems clear that better imaging tools will improve patient care, we need better ways of measuring that improvement. In evaluating new therapies, a cure or prolonging the patient's life are often important measures of effectiveness. For diagnostics, however, these measures are relatively insensitive. The problem is that survival is a global reflection of all diagnostic and therapeutic interventions that a patient experiences; it often is difficult or impossible to ascribe improvements in survival to a particular diagnostic test. More appropriate measures of effectiveness might include, for example, greater efficiency of testing, less cost, fewer hospital days, less morbidity, and the need for less extensive or disfiguring treatment. In short, we need improved methodologies to assess the ultimate value of diagnostic tests.  [National Cancer Institute, US "Scientific Priorities for Cancer Research: NCI's Extraordinary Opportunities: Cancer Imaging", March 2000]  http://2001.cancer.gov/imaging.htm 

in vivo imaging: Imaging sciences are at a stage at which in vivo imaging can occur at near micron resolutions with image specificity at the physiological, cellular and molecular level. Although the molecular basis of may diseases are well defined, we do not have a full understanding of the mechanism by which they develop in vivo nor have we fully harnessed the potential for translating advances in molecular science into clinical practice of imaging. Increased understanding of these areas and development of novel techniques is likely to provide new important directions in the earlier detection, molecular characterization and treatment of cancers. [NCI, BIP Funded Projects and Resources, Ralph Weissleder, Center for Imaging Research, Mass General Hospital, In Vivo Cellular and Molecular Imaging Centers] http://www.nci.nih.gov/bip/icmics.htm

Advances in both structural and functional imaging technologies have produced remarkable tools for understanding, detecting, and diagnosing cancer. Yet the power of these tools could be amplified appreciably if advances in imaging technology could be merged with the myriad new discoveries in cancer- related genes and proteins. A scientific gulf still exists between basic scientists who discover new cancer genes and intracellular pathways – any of which could serve as a diagnostic or therapeutic target – and imaging scientists who focus on non- invasive approaches to transform these discoveries into a greater understanding of cancer.   [National Cancer Institute, US "Scientific Priorities for Cancer Research: NCI's Extraordinary Opportunities: Cancer Imaging", March 2000]  http://2001.cancer.gov/imaging.htm 

infrared: That portion of the spectrum, with longer wavelengths, which lies beyond the visible wavelengths. For CRI devices, wavelengths between 750 nm and 1000 nm are considered "near- infrared" (NIR). For CRI devices, wavelengths between 1000 nm and 2000 nm are considered "mid- infrared" (MIR). [CRI, Inc. US,  Photon University Glossary] http://www.cri-inc.com/photon/glossary.shtml

 Narrower terms: infrared spectroscopy, Near InfraRed

infrared spectroscopy: Some of the most recent advances [in diagnostics] involve the infrared region of the electromagnetic (or light) spectrum. Infrared light was discovered in 1800 by Sir William Herschel, a British astronomer and musician, but infrared spectroscopy did not really develop until the 20th century. Used for decades in the study of molecular structures, it is now showing its true colours to the medical community. [National Research Council, Canada, Institute for Biodiagnostics "Spectroscopy"] http://www.ibd.nrc.ca/english/spec_home.htm 

ion microscopy: Use of the Secondary Ion Mass Spectrometry SIMS technique to obtain micrographs of the elemental (or isotopic) distribution at the surface of a sample with a spatial resolution of 2 mm or better.  [IUPAC Compendium]

laser: Light Amplification by Stimulated Emission of Radiation. This phenomenon is brought about using devices that transform light of varying frequencies into a single intense, nearly nondivergent beam of monochromatic radiation in the visible region. Lasers operate in the visible, infrared, or ultraviolet regions of the spectrum. They are capable of producing immense heat and power when focused at close range and are used in surgical procedures, in diagnosis, and in physiologic studies. [MeSH]  Related terms CCD, image analysis, scanning technology Narrower terms Laser Fluorescence Microscopy, laser scanning, laser scanning microscopy 

Laser Fluorescence Microscopy LFM: In LFM a laser excites molecules that have been used to stain specific entities such as proteins, nucleic acids or cellular components.  The tag molecules are chosen to have large fluorescence quantum yields, which allows them to be observed with great selectivity.  With the appropriate implementation, LFM has even proven capable of monitoring the dynamics of single fluorophores.  To achieve good three- dimensional resolution, LFM must be implemented confocally. Furthermore, the laser intensities in LFM are high enough that fluorophores can photobleach rapidly and that other molecules that absorb light at the laser wavelength can be damaged. ["Two photon microscopy" John T. Fourkas, Boston College, Chemistry Dept., Dec. 2000]   http://ch03.bc.edu/Department/Faculty/fourkas/TwoP.html  Related term two photon excitation Broader term fluorescence microscopy.

laser scanning:  Microarrays glossary Related term scanning technologies.

laser scanning cytometry: As a diagnostic research tool automatically measures laser- exited fluorescence at multiple wavelenghts (blue light up to infrared with 4 photomultipliers) on slides featuring relocation of every single cell. [3th Heidelbert Cytometry Symposium, German Society of Cytometry, Oct. 19-21, 2000] http://www.dkfz-heidelberg.de/cytometry/abstracts.htm

laser scanning microscopy: There are two major forms of laser scanning microscopy, namely confocal laser scanning microscopy (CLSM) and multiphoton laser scanning microscopy (MPLSM). The two forms are very similar at the illumination side (as opposed to the detection side). ... 

MPLSM is more sensitive that CLSM because all the light generated to make an image is sent directly to the photon multiplier tube.

This contrasts with  CLSM where a pin hole is required to select the light from the focal plane. In CLSM there is considerable loss of signal in the optics required to direct the light to the pin hole.

MPLSM gives a sharper image than CLSM because of the lack of extraneous light and improved geometry of detection. In MPLSM the photon multiplier tube can be placed very close to the specimen whereas CLSM has all the intervening optics and the pin hole. [Bruce Jenks, Dept. of Cellular Animal Physiology, Univ. of Nijmegen, The Netherlands http://www.sci.kun.nl/celanphy/Bruce%20web/scanning%20microscopy.htm

Magnetic Resonance Force Microscopy MRFM: A new microscopic imaging technique that combines aspects of atomic force microscopy AFM with magnetic resonance imaging MRI. Interest in this technique is driven by the possibility of reaching the "Holy Grail" of microscopy: true three- dimensional, sub- surface imaging with atomic resolution and chemical specificity. This goal has not yet been reached, but good progress is being made. [Science & Technology at Almaden Research Center, IBM] http://www.almaden.ibm.com/st/projects/nanoscale/mrfm/ 

Magnetic Resonance Imaging MRI: Non- invasive method of demonstrating internal anatomy based on the principle that hydrogen nuclei in a strong magnetic field absorb pulses of  radiofrequency energy and emit them as radiowaves which can  be reconstructed into computerized images. The concept includes proton spin tomographic techniques. [MeSH]

Magnetic Resonance Spectroscopy MRS: Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING). [MeSH]

Magnetic Resonance Spectroscopic Imaging MRSI: See under functional/ metabolic imaging

micro-PET: Micro-PET in small lab animals is quickly making PET the technology of choice for pharmaceutical screening. [California Nanosystems Institute, Univ. of California - Los Angeles, US "Research- Building Blocks]  http://www.cnsi.ucla.edu/research/default.htm#blocks  Broader term Positron Emission Tomography PET.  See also under nanomanufacturing Miniaturization glossary

microscopy: Narrower terms include atomic force microscopy AFM, Confocal Scanning Laser Scanning Microscopy CLSM, confocal microscopy, electron microscopy, fluorescence microscopy, ion microscopy, Laser Fluorescence Microscopy LFM, laser scanning microscopy, Multiphoton Laser Scanning Microscopy MLSM, Magnetic Resonance Force Microscopy MRFM, multiple- photon excitation fluorescence microscopy, Near- field Scanning Optical Microscopy NSOM, Scanning Electron Microscopy SEM, Scanning Transmission Electron Microscopy STEM, Scanning Tunneling Microscopy STM, scanning probe microscopy, Surface Plasmon Resonance microscopy, Total Internal Reflectance Fluorescence Microscopy TIR-FM, Transmission Electron Microscopy TEM, two- photon Laser Fluorescence Microscopy

mid- infrared MID: See under infrared

molecular distillation:A special method for transmission electron microscopy sample preparation. It is especially useful for immunogold labeling.This technology is being developed in the facility. [Analytical Imaging Facility, Albert Einstein College of Medicine, 2000] http://www.aecom.yu.edu/aif/instructions/EMPREP/mol_dist.htm

molecular imaging: Current technologies for the molecular analysis of disease are largely restricted to in vitro methods and need to be extended to the in vivo situation. Furthermore, the use of molecular probes or tracers for  imaging molecular events in pre- clinical and clinical investigations are essential for detection of molecular changes in vivo. Developments of innovative, high- resolution imaging methods at the cellular or  molecular scales are needed, with particular emphasis on identification and characterization of processes in the early formation of disease or early molecular changes during intervention or therapy. Integrations of  these emerging molecular imaging methods with advances in traditional  imaging methods are also required for more effective cancer  investigations in vivo. [National Cancer Institute, US "Development of Novel Technologies for in vivo Imaging (Phased Innovation Award)  May 29, 2001  http://grants.nih.gov/grants/guide/pa-files/PAR-01-101.html 

Molecular Imaging fuses the disciplines of molecular biology, genetic engineering, immunology, cytology, and biochemistry with imaging. Advances in MRI/MRS, MR microscopy, cellular tags, PET and SPECT are used to evaluate normal and abnormal tissue metabolism and perfusion in response to genetic, physiological, or therapeutic challenges. [NIH Clinical Center, Laboratory of Diagnostic Radiology Research, Initiatives, 2001]  http://www.cc.nih.gov/ldrr/htmlpg/Initiatives.html

Multi-isotope Imaging Mass Spectrometry MIMS: Mass spectrometry glossary

multiple- photon excitation fluorescence microscopy: A technique that uses non- linear optical effects to achieve optical sectioning. ... Advantages of multiphoton imaging: Optical sections may be obtained from deeper within a tissue that can be achieved by confocal or wide- field imaging. There are three main reasons for this: the excitation source is not attenuated by absorption by fluorophore above the plane of focus longer excitation wavelengths suffer less scattering  fluorescence signal is not degraded by scattering from within the sample as it is not imaged. [Laboratory for Optical and Computational Instrumentation, Univ. of Wisconsin Madison, 1999] Related terms two photon, three photon http://www.loci.wisc.edu/multiphoton/mp.html

Multiphoton Laser Scanning Microscopy MLSM: See under laser scanning microscopy

Multipole Coupling Spectroscopy MCS: An analytical process that enables direct measurement of structural changes that result from protein- protein and protein- ligand interaction, is a highly sensitive and rapid method that avoids the use of labels, detecting subtle changes in the dielectric properties of macromolecules, that result from interaction with other molecules. MCS can determine the binding specificity, binding kinetics, and agonist/ antagonist properties of ligand- target interactions and also allows precise and real-  time assay of DNA hybridization events at very low copy number, with potential application in SNP genotyping with minimal or no sample amplification. MCS has potential in drug target validation, high- throughput drug lead screening, lead optimization, and DNA polymorphism analysis. [John Hefti, Signature BioScience, INC. "Structural Interaction Profiling Using Multipole Coupling Spectroscopy", Advances in Assays, Molecular Labels conference, June 2000]  http://www.healthtech.com/conference/00lsd/

nanophotonics: With the ever- decreasing size of devices, optical communication technologies and control of individual biomolecules are increasingly important. The need arises to extend the power of optics to the nanometer scale... The control and manipulation of light on this scale offers new approaches to microscopy and spectroscopy, as well as to photonic devices. Ultimately this work will lead to a fundamental understanding of the manner in which organized collections of nanometric domains can communicate cooperatively .. photonic structures that enable the localization and controlled propagation of light in arrays of metallic nanoparticles ... photonic structures enable the design of optical switches and lasers on a chip. [Argonne National Lab, US "Near- Field Optics and Nanophotonics 2001] http://www.anl.gov/OPA/factsheets/I-01b.pdf

Near-field Scanning Optical Microscopy NSOM:  Permits examination of highly localized extracellular, membrane, or intracellular chemical composition, fluorescence lifetime, and anisotropy (a sensitive monitor of interacting systems) measurements. NSOM achieves sub- optical resolution, in the 100 - 200 nm range by passing light through a small aperture. Two- photon excitation has been employed in NSOM. [National Center for Research Resources "Integrated Genomics Technologies Workshop Report" Jan 1999]  http://www.ncrr.nih.gov/newspub/genomic.pdf 

Near InfraRed spectroscopy NIR: A noninvasive technique that uses the differential absorption properties of hemoglobin and myoglobin to evaluate tissue oxygenation and indirectly can measure regional hemodynamics and blood flow. Near- infrared light (NIR) can propagate through tissues and at particular wavelengths is differentially  absorbed by oxgenated vs. deoxygenated forms of hemoglobin and myoglobin. illumination of intact tissue with NIR allows qualitative assessment of changes in the tissue concentration of these molecules. The analysis is also used to determine body composition. [MeSH]

nuclear medicine: When one talks about the revolution in biology, one is talking about molecules and receptors. Nuclear medicine and PET scanning can exploit the role of receptor imaging for anti- angiogenesis therapies. Receptor imaging is an extremely powerful technique, and one that is also safe and flexible. There are physical attributes that receptors need to have. A large number (10,000 to 50,000 sites per cell) of high affinity (1 x 10^-8 and 1 x 10^-10 molar) binding sites, that are selectively expressed during the biologic process of interest and present throughout the target tissue, are necessary for receptor imaging.  Both favorable biodistribution and radionuclide characteristics are desirable with receptor imaging. The use of validated tracers to image flow, metabolism, blood volume, and permeability is recommended for the short term.  For the long term, the recommendation is to evaluate and validate new approaches to monitoring effects of anti- angiogenesis drugs. We recommend supporting the infrastructure in order to accelerate the development of Fluorine labeling of proteins for PET. [Francis Blankenberg "Nuclear Medicine/ Positron Emission Tomography" Meeting Summary Second National Forum on Biomedical Imaging in Oncology, Sept. 2000] http://dino.nci.nih.gov/dctd/forum/summary00.htm

optical biosensors: Include evanescent waves, fiber optical chemical sensors Related terms Assays, labels, signaling & detection glossary

optical laser spectroscopy: See fluorescence, Raman

optoelectronics: The merger of optics and electronics is increasingly present in our everyday lives through familiar technology such as televisions, compact disc players, fibre optic communication systems, barcode scanners in the supermarket and mobile telephones. However this is the tip of the iceberg, as the technology expands in such fields as displays, transportation, medicine, environmental monitoring, computers and construction. Optoelectronics will be the all- pervasive technology that continues the propulsion of progress in the new millennium that has been driven by electronics over the past 35 years. The Optoelectronics global market was worth over £100 billion in 1998 and it is growing by at least 18% each year. [Scottish Optoelectronics Association] http://www.optoelectronics.org.uk/

phosphorimagers: Microarrays glossary

Photo Multiplier Tube PMT: A photomultiplier tube (PMT) is a vacuum phototube with additional amplification by electron multiplication . It consists of a photocathode, a series of dynodes, called a dynode chain on which a secondary- electron multiplication process occurs, and an anode. According to the desired response time, transit time, time spread , gain, or low dark current, different types of dynode structures have been developed, e.g. circular cage structure, linear focused structure, venetian blind structure, box and grid structure . Some special dynode structures permit combination with additional electric or magnetic fields The term vacuum photodiode is not recommended. [PART XI: Detection of Radiation IUPAC Recommendations 1995 Originally authored by K. Laqua, B. Schrader, D. S. Moore, and T. Vo-Dinh] http://www.iupac.org/reports/V/spectro/partXI.pdf

photochemistry: The branch of chemistry concerned with the chemical effects of light (far UV [ultraviolet] to I.R [InfraRed]). [IUPAC Photo]

photon: The quantum of electromagnetic energy at a given frequency. This energy, E=hv, is the product of the Planck constant (h) and the frequency of the radiation (v). Related term quantum. [IUPAC Photo]

Photon-Correlation Spectroscopy: Involves the measurement of the dynamic fluctuations of the intensity of fluorescent or scattered light in a very small volume. Brownian motion causes the fluctuations in local concentrations of molecules- resulting in local inhomogeneities of fluorescence or refractive index from which details of molecular interactions and diffusive behavior can be extracted. Potentially important applications include determination of macromolecule interactions (forward and reverse rates for complex formation) and translational mobility in the cytoplasm of living cells. This method is also applicable to the study of aggregating systems. The extension of fluorescence correlation spectroscopy to multi- photon excitation regimes is logical, since smaller, better- defined excitation volumes can be optically interrogated. A limitation, and advantage, of fluorescence correlation spectroscopy methods is a requirement for low probe concentrations.  [National Center for Research Resources "Integrated Genomics Technologies Workshop Report" Jan 1999]  http://www.ncrr.nih.gov/newspub/genomic.pdf

photonic band gap:

photonics: A broad field of research encompassing optoelectronics, passive optical components, micro- optics, lasers, photoprocessing, spectroscopy, optical instruments, and optical systems, including optical interconnect and communications systems. Photonics is primarily concerned with the spectral range 160 nm to 1600 nm (end of vacuum UV to near IR).  Other important spectral regions: infrared spectrometry (2-25 um), blackbody radiation detection (8-12 um). The key building blocks of photonics are:  sources of photons,  detectors of photons,  driver and detection electronics, photon control devices (optics, waveguides, couplers etc.), and their integration in systems which may include other elements (sensor, rf device, CMOS). [NMRC National Microelectronics Research Centre, Ireland "What is Photonics?" 2001] http://www.nmrc.ie/research/photonics-group/trends.html

Positron Emission Tomography PET:  A brain imaging method in which blood flow in the brain is studied by injecting a radioactive tracer into the bloodstream, and determining the distribution of the tracer in the brain by (indirectly) detecting positrons emitted during radioactive decay of the tracer. [Introduction to Cognitive Neuropsychology Glossary, Dept. of Cognitive Science,  Johns Hopkins Univ. Version of 8/29/00] http://hebb.cog.jhu.edu/courses/105/105-g

Complementary to the anatomic imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI). Related termsmolecular imaging, SPECT.  Narrower term micro-PET, nano-PET

History of Positron Imaging, Gordon Brownell, Oct. 1999  http://www.mit.edu/~glb/alb.html

probe: Probes used in atomic force and scanning probe microscopy.  How do these relate to the probes defined in Gene amplification & PCR and Microarrays.

quantitating imaging data: Neoplasms have an intrinsic spatially distributed nature. That is, tumors develop in different sites, metastasize to other sites and are internally heterogeneous. To study tumors one must make spatially distributed  measurements. Imaging is a means of making and displaying spatially coherent measurements and is therefore a key resource for studying the development, growth and therapeutic response of neoplasms. One of the important research directions for imaging research is to provide quantitative information in the setting of cancer diagnosis and therapy. Quantitation of image data for small animals will lead the way to application of quantitative methods in human beings.

A major limitation to studying tumors in model systems with current imaging techniques is the limited availability of small animal imaging systems. Most biomedical imaging devices have been optimized for human studies and have suboptimal spatial resolution for small animals and their tumors. However, imaging techniques can be scaled down to yield very high resolution and signal sensitivity for in vivo images of mouse- sized organs. Furthermore, there are some applications of imaging techniques that could provide valuable knowledge from small animal models, but are not feasible for human subjects. [National Cancer Institute, US "Small Animal Imaging Resource Program" RFA July 31, 2000] http://grants.nih.gov/grants/guide/rfa-files/rfa-ca-01-012.html

quantum (of radiation): An elementary particle of electromagnetic energy in the sense of wave- particle duality. See photon. [IUPAC Photo]

Raman scattering: See under Raman spectroscopy

Raman spectroscopy: Involves the coupling of incident light with the internal vibrational states of molecules. Raman active transitions are about 12 orders of magnitude lower in intensity than fluorescence transitions. However, at resonance, i.e.., when the exciting light is tuned to an electronic absorption band of the molecule, the intensity of Raman scattering increases by as much as 6 orders of magnitude. When molecules are adsorbed onto appropriate metal surfaces, such as roughened silver, another 6 or more orders of magnitude increase in sensitivity is gained. Adsorption of molecules onto colloidal metal particles has yielded enhancement factors of as much as 15 orders of magnitude, permitting in advantageous cases single- molecule resonance (and non- resonance) Raman spectrum detection. SERS Surface- enhanced Raman Scattering  is thus viewed as a method with great potential for ultra- high resolution analysis of biological systems. [National Center for Research Resources "Integrated Genomics Technologies Workshop Report" Jan 1999]  http://www.ncrr.nih.gov/newspub/genomic.pdf  Narrower term SERS Surface- enhanced Raman Scattering

Raman spectrum analysis: Analysis of the intensity of Raman scattering of monochromatic light as a function of frequency of the scattered light. [MeSH]

receptor imaging: The human brain is highly complex and for normal function relies on the interaction of over 100 neurotransmitters with 300 receptors. Few techniques are available for investigating the molecular bases of human brain pathophysiology in vivo. A powerful technique is Positron Emission Tomography (PET). When used with appropriate radioligands, PET can reveal the distribution of neuroreceptors in living human brain, and their interactions with neurotransmitters or administered drugs.  [Christer Halldin (Coordinator)  Serotonin 5-HT1A Receptor Imaging in the Human Brain with PET. Coordination of the Standardization and Dissemination of Methodology STUDY, Karolinska Institut 1/11-98 - 31/10-99) Updated 6/ 21/00] http://www.ki.se/org/way/#a

receptor mapping: Maps genomic & genetic

Self- Amplified Spontaneous Emission SASE: See under tunable lasers

Scanning Electron Microscopy SEM: Any analytical technique which involves the generation and evaluation of secondary electrons (and to a lesser extent back scattered electrons) by a finely focused electron beam (typically 10 nm or less) for high resolution and high depth of field imaging.  [IUPAC Compendium]

Microscopy in which the object is examined directly by an electron beam scanning the specimen point- by- point, giving the surface image a three- dimensional quality. [MeSH]

scanning probe microscopy: Electron microscopy in which a very sharp probe is employed in  close proximity to a surface, exploiting a particular surface-related property. When this property is  local topography, the method is atomic force microscopy, and when it is local conductivity, the method is scanning tunneling microscopy. [MeSH] Narrower term scanning tunneling microscopy Related term nanoscience Miniaturization glossary

scanning technology: Scanning a fluorescence labeled DNA array is conceptually quite simple. A light source excites the labeled samples and a detector system measures and records the emitted fluorescence. However the instrumentation requirements differ based on the precise nature of the array. Most image capture instruments use a scanning detector similar to line- scanning detector  systems for DNA sequencing instruments … Clearly detector resolution is an area that must develop rapidly over the next few years. [B Sinclair "Everything’s great when it sits on a chip" Scientist 3(11): 18 May 24 1999]  http://www.the-scientist.com/yr1999/may/profile1_990524.html  Related terms confocal microscopy, laser. See also Microarrays glossary

Scanning Transmission Electron Microscopy STEM: A special TEM- technique in which an electron transparent sample is bombarded with a finely focused electron beam (typically of a diameter of less than 10 nm) which can be scanned across the specimen or rocked across the optical axis and transmitted secondary, backs scattered and diffracted electrons as well as the characteristic X-ray spectrum can be observed. STEM essentially provides high resolution imaging of the inner microstructure and the surface of a thin sample (or small particles), as well as the possibility of chemical and structural characterization of micrometer and sub- micrometer domains through evaluation of the X-ray spectra and the electron diffraction pattern.  [IUPAC Compendium]

Scanning Tunneling Microscopy STM: A type of scanning probe microscopy in which a very sharp conducting needle is swept just a few angstroms above the surface of a sample. The tiny tunneling  current that flows between the sample and the needle tip is measured, and from this are produced  three- dimensional topographs. Due to the poor electron conductivity of most biological samples,  thin metal coatings are deposited on the sample. [MeSH] Broader term scanning probe microscopy

single cell NMR imaging: NMR & X-ray crystallography glossary

Single-Photon Emission-Computed Tomography SPECT: A method of computed tomography that uses radionuclides which emit a single photon of a given energy. The camera is rotated 180 or 360 degrees around the patient to capture images at multiple positions along the arc. The computer is then used to reconstruct the transaxial, sagittal, and coronal images from the 3-dimensional distribution of radionuclides in the organ. The advantages of SPECT are that it can be used to observe biochemical and physiological processes as well as size and volume of the organ. The disadvantage is that, unlike positron- emission tomography where the positron- electron annihilation results in the emission of 2 photons at 180 degrees from each other, SPECT requires physical collimation to line up the photons, which results in the loss of many available photons and hence degrades the image.  [MeSH]

spectral imaging: A relatively novel technique that uses precise measurements of optical spectra at every pixel of an image in order to overcome these deficiencies and thereby to appreciate differences in color that might otherwise be inapparent. Sophisticated algorithms can be used for the extraction of maximum information from the analyzed scenes. When general histology stains are used, spectral analysis can uncover unseen specificities in staining behavior; when specific probes are applied to tissue, spectral imaging can help disentangle multiple colors, even when they overlap either spectrally, spatially, or both. [Richard Levenson, Clifford Hoyt "Spectral Imaging and Microscopy" American Laboratory ]  http://www.iscpubs.com/pubs/al/articles/a0011/a0011lev.pdf.

spectrophotometry:  The art or process of comparing photometrically the relative intensities of the light in different parts of  the spectrum. [MeSH]

spectrometry: Narrower terms: Multi- isotopic Imaging Mass Spectrometry MIMS, mass spectrometry

spectroscopy: Narrower terms circular dichroism spectroscopy, Fluorescence Correlation Spectroscopy, Fourier Transform InfraRed Spectroscopy, Magnetic Resonance Spectroscopy, Near InfraRed Spectroscopy NIR, Photon Correlation Spectroscopy, Raman spectroscopy, Surface Enhanced Raman Spectroscopy SERS, X-ray Photoelectron Spectroscopy XPS

Surface Enhanced Raman Spectroscopy SERS: Used to investigate the vibrational properties of adsorbed molecules. Metal surfaces have to be of high reflectivity and of a suitable roughness. Increasing sensitivity of detectors these days means that Raman spectra can be observed in very thin films without the need for the surface enhancement effect. [Surface Analysis Forum, Surface Science Site, 2001]   http://www.uksaf.org/tech/sers.html  Broader term Raman Spectroscopy

Surface Plasmon Resonance [microscopy]:. Surface plasmons are optically stimulated by laser illumination of a metal film. These electromagnetic waves travel along the interface between the metal and a dielectric layer. The magnitude of the electromagnetic field close to the surface is extraordinarily sensitive to interface processes - in the BiaCore instrument, to receptor/ ligand interactions, which cause local refractive index changes. Since the vertical resolution of the surface plasmons extends from subnanometer to hundreds of nanometers, surface plasmon microscopy is potentially useful for the study of cell membranes, and transport and trafficking processes involving the membrane, as well as for studies of cell- nanofabricated surface interactions. [National Center for Research Resources "Integrated Genomics Technologies Workshop Report" Jan 1999]  http://www.ncrr.nih.gov/newspub/genomic.pdf   Broader term Surface Plasmon Resonance Assays, labels, signaling & detection glossary

succesive absorption: See under two photon excitation.

three- photon excitation: Can also be used in certain circumstances. In this case three photons are absorbed simultaneously, effectively tripling the excitation energy. Using this technique, UV [ultraviolet] excited fluorophores may be imaged with IR [InfraRed] excitation. Because excitation levels are dependent on the cube of the excitation power, resolution is improved (for the same excitation wavelength) compared to two photon excitation where there is a quadratic power dependence. It is possible to select fluorophores such that multiple labeled samples by can be imaged by combination of 2- and 3 photon excitation, using a single IR excitation source. [Laboratory for Optical and Computational Instrumentation, Univ. of Wisconsin Madison, 1999] Related terms two photon, multi- photon http://www.loci.wisc.edu/multiphoton/mp.html

tomography: Imaging methods that result in sharp images of objects located on a chosen plane and blurred images located above or below the plane. [MeSH] Narrower terms Positron Emission Tomography PET, Single Photon Emission Computed Tomography SPECT

Total Internal Reflectance Fluorescence Microscopy TIR-FM:  Is based on the generation of an evanescent wave generated by total internal reflection at the boundary between media of differing refractive indices. The evanescent wave propagates in a direction normal to the interface for a short distance. Thus, it is useful for excitation of molecules in the vicinity of the surface- permitting membrane binding/ adsorption studies without the need to separate bulk phase ligand. Evanescent waves have been generated utilizing two- photon excitation with an accompanying decrease in the sensing depth. [National Center for Research Resources "Integrated Genomics Technologies Workshop Report" Jan 1999]  http://www.ncrr.nih.gov/newspub/genomic.pdf  

Transmission Electron Microscopy TEM: Any technique in which an electron transparent sample is bombarded with an electron beam and the intensity of the transmitted electrons which is determined by scattering phenomena (electron absorption phenomena) in the interior of the sample is recorded. TEM essentially provides a high resolution image of the microstructure of a thin sample. This technique is often just called electron microscopy. The term transmission electron microscopy is however recommended for the sake of a clear distinction from other electron microscopic techniques. [IUPAC Compendium] Broader term electron microscopy, Related term molecular distillation

tunable lasers: X-ray lasers are expected to open up new and exciting areas of basic and applied research in biology, chemistry and physics. Due to recent progress in accelerator technology the attainment of the long sought-after goal of wide- range tunable laser radiation in the Vacuum- Ultraviolet and X-ray spectral regions is coming close to realization with the construction of Free- Electron Lasers (FEL) based on the principle of Self- Amplified Spontaneous Emission (SASE). In a SASE FEL lasing occurs in a single pass of a relativistic, high- quality electron bunch through a long undulator magnet structure. [J. Rossbach, "New Developments on Free Electron Lasers Based on Self Amplified Spontaneous Emission" , Particle Accelerator Conference, Chicago IL, US, June 18- 22, 2001]  http://pacwebserver.fnal.gov/papers/Monday/AM_Oral/MOAL003.pdf. 

two- photon excitation: Excitation resulting from successive or simultaneous absorption of two photons by an atom or molecular entity. This term is used for successive absorption only if some of the excitation energy of the first photon remains in the atom or molecular entity before absorption of  the second photon. The simultaneous two- photon absorption can also be called biphotonic excitation.  [IUPAC Photo]  

Two-photon excitation results from high laser fluxes leading to simultaneous absorption of two photons whose energies sum, permitting excitation of chromophores at /2. Thus, two- photon excitation using 900 nm light will excite a chromophore absorbing at 450 nm. Two- photon excited fluorescence intensity is proportional to the square of the exciting laser intensity. The confined two- photon excitation volume greatly reduces out of focus excitation. The capability of using near- IR excitation wavelengths provides two- photon excitation scanning microscopy the advantage of much- reduced cell damage compared to single- photon confocal microscopy, since there are few intrinsic near- IR absorbing chromophores. Two- photon illumination has been used to release caged compounds in femtoliter volumes. [National Center for Research Resources "Integrated Genomics Technologies Workshop Report" Jan 1999]  http://www.ncrr.nih.gov/newspub/genomic.pdf 

Related term biphotonic excitation.  

Two-photon Laser Fluorescence Microscopy: The excitation wavelength is in the near infrared, a region of the spectrum in which there is virtually no absorption in cells or most chemical systems.  Excitation of the fluorophore occurs via the simultaneous absorption of two photons of excitation light. The two- photon process has a small absorption cross- section, and the rate of absorption is proportional to the square of the instantaneous intensity of the excitation laser.  By employing a laser that can generate ultra short pulses, high peak intensities can be generated at low average power.  Thus, efficient two- photon excitation can be achieved with minimal photo damage or photobleaching. Furthermore, the light intensity is great enough to create significant two-photon absorption only where the radius of the laser beam is extremely small. Since a laser beam can be tightly focused only for a short distance, the two- photon excitation volume is small and can be translated in all three dimensions.  Finally, the wavelength of the excitation light (and the Rayleigh and Raman scattering associated with it) is considerably different from that of the fluorescence that it generates, which can greatly increase the signal to noise ratio for detection  ["Two photon microscopy" John T. Fourkas, Boston College, Chemistry Dept., Dec. 2000] http://ch03.bc.edu/Department/Faculty/fourkas/TwoP.html Broader term Laser Fluorescence Microscopy

wavelet: <mathematics> A waveform that is bounded in both frequency and duration. Wavelet tranforms provide an alternative to more traditional Fourier transforms used for analysing waveforms, e.g. sound. The Fourier transform converts a signal into a continuous series of sine waves, each of which is of constant frequency and amplitude and of infinite duration. In contrast, most real-world signals (such as music or images) have a finite duration and abrupt changes in frequency. 

Wavelet transforms convert a signal into a series of wavelets. In theory, signals processed by the wavelet transform can be stored more efficiently than ones processed by Fourier transform. Wavelets can also be constructed with rough edges, to better approximate real- world signals. For example, the United States Federal Bureau of Investigation found that Fourier transforms proved inefficient for approximating the whorls of fingerprints but a wavelet transform resulted in crisper reconstructed images. [FOLDOC]

X-ray Photoelectron Spectroscopy XPS: Technique for determining the elemental composition at a solid surface by measuring the energy of electrons emitted in response to X-rays of different frequency. Has been applied to solid- phase combinatorial chemistry by incorporating a tracer atom in the linker. [IUPAC Combinatorial]

Bibliography

[CRI] Inc. US,  Photon University Glossary 60+ definitions.  http://www.cri-inc.com/photon/glossary.shtml

Glossary of Molecular Imaging Terminology, In Vivo Cellular and Molecular Imaging Centers, NCI,  190 definitions. http://207.238.28.154/NCI-BIP-ICMIC/glossary.asp  

[IUPAC Photochemistry] International Union of Pure and Applied Chemistry, Glossary of Terms used in Photochemistry, Pure and Applied Chemistry 68 (12): 2223-2286, Mar. 1996.  400+ definitions http://www.unibas.ch/epa/glossary/glossary.pdf

[Photonics] Dictionary, Laurin Publishing Co. Inc. 5500 definitions. http://www.photonics.com/dictionary/ 

World Wide Web Virtual Library: Microscopy, Gregory Strout, Ohio State Univ. http://www.ou.edu/research/electron/www-vl/long.shtml

Alpha glossary index

IUPAC definitions are reprinted with the permission of the International Union of Pure and Applied Chemistry.

In-depth Imaging glossary

BIP Biomedical Imaging Program: National Cancer Institute, US program  http://www.nci.nih.gov/bip/default.htm

DCIDE Development of Clinical Imaging Drugs and Enhancers: A new program designed to expedite and facilitate both the development of promising imaging enhancers (contrast agents) or molecular probes and their translation from laboratory synthesis to IND application. Under this program, developers of a promising diagnostic agent or probe can apply to the National Cancer Institute (NCI) for assistance. NCI will make its pre- clinical development resources available to competitively- selected developers in order to remove the most common barriers between laboratory discoveries and IND status.

The DCIDE program is intended to supply or enable missing steps to those who lack development capacity or resources so that promising discoveries may eventually be translated to the clinical research environment. The DCIDE program will focus on promising diagnostic agents that are not otherwise likely to undergo adequate pre- clinical testing to warrant an IND application. The DCIDE program itself will not provide full- scale clinical development but will facilitate the performance of the pre- clinical studies necessary to bring an imaging agent to IND status. [National Cancer Institute, DCIDE, FAQ] http://www.nci.nih.gov/bip/DCID_faq.htm#what

Interagency Council on Biomedical Imaging in Oncology: A newly created multi-agency group designed to serve as a sounding board for investigators and manufacturers attempting to take emerging medical imaging technology to market. It consists of a core staff from the FDA [Food and Drug Administration], HCFA [Health Care Financing Administration], and NCI [National Cancer Institute] with experience and knowledge concerning the decision- making processes for their agency for medical imaging products. Additional agency staff may be added to the core group on specific matters when needed. The purpose of the Council is to provide multi- agency advice that may help guide imaging technology developers in the fight against cancer. The Council will provide advice on projects or project proposals brought voluntarily by investigators and technology/ device developers in industry and academia. It offers a new, multi- agency perspective to the communication with government agencies that is already available to investigators and companies. [National Cancer Institute "Resources for Scientists" 2001] http://cancer.gov/scienceresources/announcements/imaging.html

National Institute of Biomedical Imaging and Bioengineering: Newest NIH institute. ["NIBIB Acting Director names" NIH News Release May 9, 2001] http://www.nih.gov/news/pr/may2001/nibibod9.htm   Temporary NIBIB website http://grants.nih.gov/grants/becon/becon.htm