Original Repository: Stanford University Libraries. Department of Special Collections and University Archives. Paul Berg Papers
Reproduced with permission of Michael G. P. Stoker.
Medical Subject Headings (MeSH):
Protein Synthesis, Tumor Viruses, and Recombinant DNA, 1959-1975
Letter from Paul Berg to Michael G. P. Stoker (February 23, 1973)
1st February, 1973
This is just a brief progress report. You should by now have had the large batch of ST6 cells for testing. I hope they arrived
safely. I also asked Bill to arrange for you to get a fresh batch of BHK clone C13 and to send you literature on the spiral
bottles cell production system.
The transplantation antigen on ST1 cells is at the moment under test again. This time I have included an SV40 transformed
BHK as a control as well as ST6.
Dr. Andy Louie, the postdoc who seemed to me to be a good person to repeat the isolation of abortive clones and to bring them
to you for testing, has now opted for a different problem, namely a study on the histone-like proteins in the polyoma virus
capsid and their relationship to the DNA. He is moving to Lionel to do this. I did not feel like dissuading him since the
abortives project may not be so interesting now after all. However, during the last month or so he has isolated about ten
abortive and stable transformants from a methocel transformation. They are in the freezer in case we want to do them later.
Now about the supposed partial genomes in ST1 and ST2 (and ST6?). All the ST series came from a single plate in one experiment.
The cells were layers of BHK which had been held in low serum and which were then infected by the method Joyce Taylor was
using for the interferon studies. After four days in low serum they were suspended and plated for colonies. On one plate
with 4 x 105 cells there were 75 transformed foci on a background of normal cells. 6 of these (ST1-6) were picked, grown
It might be something to do with the low serum, or it might be keeping the infected cells at high density for several days
before replating and thus allowing opportunity for re-infections from the lytic cycles. Anyway, I have now arranged for this
to be repeated as soon as possible. We will isolate 5 more clones in the ST series (starting from scratch but infecting low
serum cells), grow them into large batches and if you are willing and interested will send them to you for testing, as well
as to Vittorio Defendi for T-antigen.
I hope that there is some progress with Helene Smith's repeat experiment.
Geoff Clarke is now back after the Biohazard Meeting which he found valuable. I am very grateful to you for letting him come,
and it will be good to see the record of the proceedings.
The reports of the ICRF departments for the review will be ready in a few weeks and we will be sending them on to you by air
mail around the end of this month. It will be good to see you in May. The Queen is visiting the laboratories at about that
time so perhaps she should join the review committee.