Original Repository: Alan Mason Chesney Medical Archives. Daniel Nathans Collection
Reproduced with permission of David C. Ward.
Medical Subject Headings (MeSH):
DNA Restriction Enzymes
Restriction Enzymes and the "New Genetics," 1970-1980
Letter from Daniel Nathans to David C. Ward (February 22, 1971)
16th March 1971
Dear Dr. Nathans,
Many thanks for sending the prep of restriction enzyme. It arrived in good condition a week or so ago. I've assayed it
on 14C-SV40 DNA and it gave only a little less activity than you quoted, based on a 5 minute incubation. I could not, however,
get detectable cleavage beyond 10 minutes. The preliminary results suggest that enzyme treated SV40 DNA will be O.K. as a
starting point for strand preparation. I shall now start to prepare a large batch of the B restriction enzyme so that we can
process about 100 [micro]grams of DNA. I'll let you know how things progress if the communications systems stay open (your
letter of January 25th arrived today -- thanks to the postal strike). I hope I can get the project finished by June as I'm
scheduled to take up my appointment at Yale in July. If you have any more information on the properties of the restriction
enzyme that might be useful I'd be extremely grateful.