UNIVERSITY OF CALIFORNIA

VIRUS LAB 0 RATORY
BERKELEY 4, CALIFORNIA

January If, 1955

Dr. Rosalind Franklin
Birkbeck College Crystallography Laboratory
21 Torrington Square
London, W. C. 1,
England

Dear Rosalind:

  Thank you very much for sending your Isanuscript in advance
of publication.
results, among them being Dr, William, from whoa you have doubtless
heard by now.

Several of us were very much interested in your

Dr, Fraenkel-Conrat and I found Wst nothing to quarrel with

you about on the chemical side and T, at least, am not able to
follow you very well on the crystallography.
connection with the first page of the manuscript that most people
use the figure 6% for the quantity of RNA in TW.  The portion of
the paper which interested me a great deal is the evidence for the
presence of some water within the viral particles.
really the case then we chemists picture a variety of chemicals
penetrating the interior of the virus to react with various things.
I mill, of course, have to revise my argument concerning the location
of the nucleic acid in the virus since it was based on the conception
of an anhydrous particle.

I might suggest in

If this is

  In connection avith the materials which we sent you, Dr, Fraenkel-
Conrat says that the I-TMV contains about 0.74% iodine, which is about
one iodine per 17,000.  Hore of this material is available if you want
it.
and we shall try to send the next ones under moist- conditions.  The

1 1 CV4 has a higher isoelectric point than !IW and since it is insoluble
\in its isoelectric zone, is inclined to come out of solution as a
j'white precipitate, particularly when the salt concentration is low.

You muld probably find that the white precipitate you observed would
dissolve readily if a bit of dilute ammonia were added or dilute
alkali of any kind.
reduce gel formation exceedingly.
should like to have it.

I am sorry that the samples did not arrive in better condition

Addition of a trace of salt will also tend to

We can provide more CV4 also if you

Since you did not request the return of the paper, may I assme

that we way keep this for reference and further study?

CAK/mla

,

C. A. Knight

c