October 26, 1956

Dr. R. FE. Strange
MiorobLological Research
Porton, Wilts.

Dear Dr. Strange:

The subject may seem remote from my special interests in bacterial
gemtics, but I would be grateful to you for reprints on your current
work on bacterial walls. We are in fact currently working on the [-forme
of BE. coli, en the basis of some observations cited in the enclosure.

Y will be heppy to exchange these publicatione when the reprints have
com in.

Tt underatand you have idantified the omino-sugar as a 3-lac tyl-giucosamine.
A compound as important as this clearly deserwas a distinctive trivial nan ;
I wuld offer forgyour consideretion "phragmose", but hope you can devise
one more euphonious.

As pert of our present study, we are searching for wall-less mutants
of F. coli-- the congeners of Davis’ diaminopimelic-less, which forms proto-
plaste when deprived of dap in 4 protective medium. It seems likely that we
shall find one which might be defective in the formation of "phasgmose” ,
but the problem wll be to maintain and identify such mtanta. what would
you recommend as the handiest source of crude "phragmose"? Would you be in
a position to furnish a small quantimkty of the purified material for specific
identification purposes? I realize this my be an inordinate request, but.
would also propose that such a amtant would be quite valuable for assay purposes.

We are also somewhat strapped for DAP, though we can gat along with the
filtrates of Davis' lysine mtant. Can you suggest where as much as 1 gn.
might be purchased?

If you can offer any further suggestions of components thatwould be relevant
to this mutant hunt, I would be glad to have then.

Yours sincerely,

Joshua Lederberg
Professor of Genetics

P.S. Please give my regards to Db. Powell when she returns. Some of these
questiogs might as well have been addressed to her. I am sorry I was unable
to have a longer disctssion with her about thie when she visited Madison recently.