Homogenize tissue and pellet nuclei a. To 4 g of young leaf tissue in a 50 ml centrifuge tube, on ice, add 20 ml of ice-cold cotton extraction buffer. The ground sample should then be placed in the indicated volume of buffer, and put on ice. Return sample to ice.
Repeat steps a-c for next sample.
Lyse nuclei a. Add 8 ml cotton lysis buffer to each sample. Resuspended nuclei pellet by vigorous vortexing. The genomic DNA is still protected by the nuclear envelope. Incubate 20-30 min.