1. collect piece of tissue (e.g., pieces of a leaf or flower) in Eppendorf tube containing 40 ml 0.25 N NaOH
2. put in boiling H₂O for 30 sec (optimum may need to be determined for each type of tissue, for floral tissue 30 sec is fine)
3. neutralize by adding 40 ml 0.25 N HCl and 20 ml 0.5 M Tris-HCl pH 8.0, 0.25% (v/v) Igepal CA-630
4. boil for another 2 min
5. use directly for PCR or store at 4°C for up to several weeks
6. if stored at 4°C boil again for 2 min before the PCR

Remarks:

Materials: