“…30 percent of the generation time). Improved resolution can be attained After release from the first block, the culture is allowed to incubate in normal medium for a period greater than S have been discussed at some length by Mazia (10), and the rate at which desynchronization occurs has been considered by Engelberg (11 (4) suggest that deoxyguanosine inhibits DNA synthesis at concentrations which do not affect production of the other deoxynucleosides.…”