August 25, 1956

Dear @rskovs:

I have had a chance to review my notes, and to clean up some of
the doubts about the cultures you types.

WG-52, 53, 54 and 55 are indeed the type strains for 0 groups
18,20,21 and 25 respectively. They had dormerly been received from
Kauffmann and found to be fertile with strain K-12. These may therefore
be xhux the most useful strains for immediate immunogenetic studies, in
the event that fertile strains of 055, Oill, ete. are not found. I would
therefore urge that you bring with you, as far as possible, teat sera
for the antigenic components which you know to occur in these strains.” Do
they have a classifxfiable K component? WG4 would also be useful, but
already belongs to 0-25. Can you type this for K antigen? The other serums

that my be important are 055, O11] and 026, and the correspomling B serums xetnx

(4nsof4r as you can separate them in practice).

With the help of your biochemical diagnoses, I have also been able to
clear up the admixture of WG52 in stock of WG53, and WG54 in stock of WG55.
These cultures have passed through many people's hands, and I have not closely
followed the current stocks. However, we do have some tkhex older stocks,
as well as lyophil preservations, which correspond chrrectly to the biochemical
diagnoses. In addition, fortunately, the biochemical mutants which were pre-
pared some time ago are uncontaminated and correct in their reactions.

wie
WG57 I do not mmudkexxmin understand; it was received among a collection

from Ewing, and originally labelled 055. There may have been a typographical
error.

I agree that it would be most advantageous if you could continue to have
necessary serums made at your own laboratory while you are in residence here.
We can therefore very well afford to wait until your arrival to pland further
what needs to be made. ‘

The only other thinga I can suggest to you are to accumulate a variety
of coli strains that may interest you to be surveyed genetically and for the
presence of lysogenic phages. Perhaps the test strains themselves, for the
O and the K series (is there a special one for H?) would be the most prac-
tical. We have gone through 0-1 through 0-25, but even these should be repeated
as we have much better @etkods now for detectahg crossability. This should
make quite a parcel! I would however also suggest a screening of as many
055, Olll ete . strains as possible; the genetic relationship of the O and the
B antigen makes for an interesting theoretical as well as practical
problem.

I have not heard lately from Dr. Heumann, but he wrote some time ago
that he was having difficulties about his fellowship. I do not know the
current status of his application; it seems possible he will not be able
to come, but I am waiting to hear from him about this.

You have not told me just how long you are planning to stay in the
lab here. We are making some plans of our own for next summer; if you
plan to do any travelling in the U.S., that would be the most apt time .
I assume we can discuss these details more meaningfully when we meet.

With haat. wishes.