THE COLORADO FOUNDATION FOR RESEARCH IN TUBERCULOSIS GERALD B. WEBB MEMORIAL BUILDING, AT THE UNIVERSITY OF COLORADO MEDICAL CENTER 4200 East Ninth Avenue Denver 20, Colorado January 2, 1958 Dr. Joshua Lederberg Department of Genetics University of Wisconsin Madison, Wisconsin Dear Joshua and Esther: Thanks for the cards and letters from various places. I sup- pose you were glad to get home and resettled even though some of the places you visited may have had things to recommend theme Regarding the reprints of the New York Academy of Science article I have not yet received any, although it is 13 months since submission of the manuscript and nearly 6 since the reprint order was submitted. Since a portion of the reprints are purchased by the Dean of the Medical School here, two of his accounts have encumbrances outstanding now for nearly six months. The N.Y. Academy isn't going to increase my popularity with him. I'm disappointed in the Academy's performance. You might advise me of the number of reprints you will need (I ordered 750, I believe). I received 10 copies of the monograph itself, and if you would like any of these let me know also. With regard to the visit hers, you could send me the times that you would be able to come. I have talked the matter over with Ted Puck and Roger Mitchell and it was the unanimous feeling that it would be better to get you out for a week or two rather than a simple stop= over in passing through. Check your schedule and advise me. Work wise things are finally getting out of the rut. I for- get all the things I scribbled by hand last time. Anyhow, (1) three experiments using X-irradiated Hela cells (sufficient radiation to give no surviving colonies) and sperm (in one case, packed together in the centrifuge) failed to give any colonies, even after prolonged incubation. It looks like micro-invection will be necessary. (2) Still haven't gotten growth of transducing lambda with our phage or Weigle's. However, at high survival I was beginning to get suggestion of growth (2X) but the indicator (W3079) went bad and we just succeeded in isolating another. (3) I have a Staph with several markers (Erythromycin, Strepto- mycin, novobiocin resistances, lysogenic lac™ -= we can get other fermentation markers also). The phage is UV inducible and I think trans- fers S& ang E* put with very low frequency. The reservation is that I have not assessed killing by the phage. You might advise me of Ruth Korman's progress especially as to her degree and what she plans about publishing her work. (4) I came across an interesting bacillus for the Dr. Joshua Lederberg Page Two January 2, 1958 following reasons: (a) it produces an antibiotic, different as far as I can tell, from all others, active on both coli and Staph. ($s$). Even if it is not worth anything commercially, it is possible to obtain resistance to the antibiotic in both coli and staph and so I've got two new markers at least; (b) the bacillus requires only glutamic acid, the requirement is relieved by reversion. I've made the stocks for skp but as yet have not made the test. I received a copy of Hollander's Oak Ridge Program recently. On paver it looks good, and since I never did get to Gatlingburg while at Oak Ridge, may be I'l] go. I see luca is to be in this country for awhile. If you are sure of his schedule you might send it to me also. With regard to our unfinished business, I wish you would look over the outlines of th: proposed papers and see if you can come up with any other forms. I am not satisfied with what we have and have not been able to devise anything that didn't look like "notebook dumping". I received a card from A, Campbell saying that he had repeated all the UV exveriments that I did and had a counle of minor facts to add. Adding excess non-transducing vhage to UV'd transducing phage and plating on sensitive recipient gives heterogenotes, whereas stable sensitives are the result when UV'd phage is used alone. There was another point that is not clear to me about rescue of a phage allele (ht) when UV'd h transducing phage is used on ht recipients. Let me hear from you. Sincerely, orse, Ph.D. MLM: re P.S. When did you get the glassine weighing papers that you have?