Septeaber 29, 1952

Dear Horton:

From comments by many people, I learn that your presentation at Ithaca
was most successful. ZI was pleased, but not surprised to hear this.

Now I have some bad news. Going into the lyophilised Salmonallas, I found
that the sealing-off of the tubes was not very well done es Shehwhéle, so that
very many of the tubes were lost. About 1 tube in every 4 or 5 is broken,
spilling over with moisture absorbed by the Caleium Chloride. The storage en-
velopes are rather measy, but are being culled now. ‘The technical defects
that are responsible are: 1) fused calcium chloride near the neck, 2) glass
pulled out too thinly, not having been adeqmtely thickened, and 3) the sealed
glass having been pushed directly back, rather than carefully melted down to
give a stronger bead. If you propose to contime this method of presefwation,
these points have to be watched, which ise why I mention then.

Not very many cultures are irreparably lost, juat ae a consequence of the
Pokshon distribution of breaks, but quite a number are represented by only a
single tube. When time permits, I will regenerate the more important of these.
Quite a few tubes have been oponed already, and every one that wae technically
satisfactory has been grown out very nicely. I can't give you a full list of
the losses, as only a couple of boxes have been examined. The most important
so far are 3W~36 (the Webster strain), LT~18 (#100), and SY-23. Less important
aleo: LTl4(altern. 11412); LT-3 (al. 525); LT-9 élte. 497 and 504). I will
send you full details when we have gohe over the entire collection. Meanwhile,
it would be helpful if you could send a list of the set you took with you, and
hot throw ettaanything until the damage is assessed. The situation is far from
catastrophic, but it is unfortunate that our sense of accurity in the integrity
of the collection should be impaired.

Stocker must have given you a full account of the sunmer's work. Esther and
I certainly enjoyed his visit very much. Since I got back from vacation, I've
taken up with Salmonella again, The "spontaneous" 4 from SW-543 was almost certainly
an error. In addition to Stocker's set, I have some more since, evidently all b-—.
Bruce's explanation of two closely linked factors, one for flagella; the other
forbthe H-antigenic type sounds very plausible, but it's a pity we still don't
have another case whebe the components are individually and independeskly recog-
nizable, I am in the midst of an attempted confirmation, by throwing in FA for
other flagellar types. I have what lake likes very satisfactory preparations
of PLT-~22/ on 3. abony, dublin-0, sandiego and Bruce set some up for para B (diphasic
and phase II). The transductions have gone, and serological tests are in progress.
If in each case the motile fopmd from SW-5&3 are a mixture of b and the FA type
the two-loous hypothesis seems fairly secure.
Did we have some b serum, or did it all go into typhng reagent? I can't
find any. Also there is a bottle labelled pullorum serum (DTB), with an additional
note on it "IXeabsorbed". Does the latter mean anything? One adhesive label wad
pasted over a paper label, the latter with your handwriting.

Joy Balm just gave me your note. If you have SW-36 (as I suppose you mst)
could you send it back for the vaccine, or can Schneider or yourself recommend a
better one?

Larry and Esther are collaborating on the "gal-duction® story. Except for
the restricted range, the stor is not essentially different from Salmonella, but
I think we can do better on mechaniam, as the types of response to lambda are
more clear cut, and we are less likely to be confused by extraheous phages. (And
of course we have sex). ‘“cwever, many of the "gal—ductions" are unstable, from + to -,
and this moved ms to look further into this in Salmonella. As I recall you had
done quit quite an dmtensive atudy on a few isolates, but had not looked at a great
many. However, 16 additional separate Gal+ in SW-435 + FA~PLT22/2 were all certainly
stable, I have some more tests in the mill, but no expectation of any differenca,

I tried to induce SW-543 to H+ with UV: no luek at all, in what should have been
a very sensitive test systea.

As you can see, my Salmonslla work is all odds and ends for the moment. I aa
waiting for Spicer to arrive before planning a definite program. Perhaps you will
see him this week. Tom Nelson is here, and moving along very nicely with kinetic

experiments, efc. on Afr. How are you progressing yourself in setting up your
lab, and so forth?

Sincerely,

yer oo 7
SJoshua Lederberg

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