I actually do it from liquid cultures, but it can be adapted for colonies. Spin down 0.5 ml of an overnight. Resuspend in 1 ml water, spin down again. Resuspend in 1 ml water. Transfer 50 ul to a small tube, incubate 5' at 95C. Add 50 ul 2x PCR reaction mix, overlay with oil, PCR. Daniel Mytelka mytelka at mendel.berkeley.edu