February 4, 1953
Dear Al:
I wouldn't want to call any phage "DNA-less", but it would be well worthwhile to look at Salmonella PLT-22, or perhaps better a lytic variant, "22V".  If you like, I'll be glad to send you these plus a few indicators (S. typhimurium), as soon as I get back to Madison.  I need hardly mention to you that typhimurium is supposedly pathogenic, but so long as nobody eats the stuff, there should be no trouble,
Yours sincerely,
Joshua Lederberg
P.S. For other reasons, I would recommend lambda on the K-12 indicator W-1485, but this might be technically more difficult, though quite high titer lambda can be gotten by lwoffing.  However, adsorption is a mess, while PLT-22 should go very cleanly.