Original Repository: Alan Mason Chesney Medical Archives. Daniel Nathans Collection
Reproduced with permission of Joanne Nathans.
Restriction Enzymes and the "New Genetics," 1970-1980
Letter from Bernard Weisblum to Daniel Nathans (November 16, 1973)
December 11, 1973
The gels, especially cylindrical ones, are fine. The agarose run clearly indicates that both JC and BK have short DNA, i.e.,
defectives. Presumably, these had not been recently plaque-purified. (We have been using agarose electrophoresis to detect
and isolate deleted genomes.) This also accounts for the many minor bands after Hin A, B, C+D, E+F, G, H, I, J, K. Presumably
failure to separate C and D, and E and F is due to the gradient gel; we use straight 4 percent acrylamide. The major point
is well made.
For further work on the DNA, you should plaque JC and BK serially twice and pick a plaque each time from a dish containing
<5 or so plaques. Grow stock from the plaque. In my experience, a plaque aspirated with a Pasteur pipette has several
With best regards,
P.S. As I mentioned to you earlier, Theresa Lee, in my lab, had also found that BK DNA (from Ken Takemoto) gives a totally
different Hin digest than SV40.