December 13, 1972
Dear Michael,
I'm disappointed that you won't be coming to Asilomar as I'd looked forward to your visit and the opportunity to both talk science and to show you a part of California you may never have seen.  But I do understand the pressures of other chores and it certainly is all right for Geof Clarke to come in your place. If you should change your mind and wad to come as well, we'd be delighted to have you both.
Your letter about the "abortives" project has not yet arrived so I'll look for that. Meanwhile I did tell Renato last month of the most recent result of H. Smith.  One of their abortive clones, which had been kept in Bethesda and had been positive for SV40 DNA sequences, was regrown under the old conditions in Bethesda.  The DNA wan isolated as before and tested by M. Martin; no viral DNA sequences were detected. Martin then re- tested an old cellular DNA preparation which on previous testing was positive for SV40 DNA and this too proved negative.  There seems to be something funny about the earlier tests (host DNA in the viral DNA preps doesn't seem to explain the finding because of negative results with uninfected cells) but I and they don't know what it could be.  Some further experiments were in progress but I've not heard of those results.
Millie and I send our best to Veronica and the family; also say hello to Renato and Maureen, Ponti and the rest of the people in the lab.
With best wishes for a happy Christmas and New Year,
Sincerely,