THE UNIVERSITY OF WISCONSIN
        THE MEDICAL SCHOOL
           MADISON 6

MCARDLE MEMORIAL LABORATORY

FOR CANCER RESEARCH

Dr. Arthur Kornberg
Iiational Institutes of Health
Bethe sda l!+, Xaryland

Dear

Gr.

Kornberg :

I received your letter of Xove:Yberls. Like you, I am

at a loss to understand ou? discrepancies in phosphate analyses.
The preparation we sent you analyzed 975 wl th glucose-6-phosphate
dehydrogenase 011 our flrst assay, uncorrected for water. 9x1.
I'uellsr suggested a check and a secoiid woiching which was very
stingy (2.5 mg. on ordinary analytical balance) gave an assay
of 1155.  'Je thought the first assay was probably correct and
sent the preparation on, since you would assay it anyhow.
After sorre 13 days, we found,  as you did, a lower assay (69,73,<).
I find 11.55 phosphorus.
seemed to have stabilized at TO$.  But now it has material in
it which causes the hydrosulfite assay to be much higher than
the enzyme assag. Yesterday I finally found time to run the
material on a chromatogram. Usin& a batch of charcoal which
has always given essentially complete recoveries with other
pr&eparations, I obtained only 405 recovery. This seons to con-
firm the suggestion that it is contaminated with metals and
makes further work with this particular batch useless.

:"?e reassaged St later and the material

     At present I have no need for TPN in my own research
and Dr. Mueller has finished the work in which he required it.
I am engaged in two problems which involve collaboration with
other members of our staff. I'ressure from them to get on with
outr collaborative work makes it difficult to justify taking
time out just now to start another batch of TFN. I very much
regret it, but feel I must leave this matter up to you now. I
note that you stated in your earlier letters that you were
really satisfied v&th the results obtained on your own prepara-
tions WVe valid, that they are free of phosphorus bearlng
contaminants. May I sugzest you go ahead with you=. publication.
!Ve would prefer you omit any consideration of our help unless you
w;sh to coimient on receipt of' our manuscript before publication.

It is worth noting that this instability of TPX when

trace metals are present is not confined to TPX. Sclilenk found
that DFN preparatlons containing traces of alminuq from alurnina
columns exhibit similar instability. We havg had preparations
around long enough to be certaln this instability is not found
routinely. It is observable in another old sample I have left,

?age No. 2

Dr. Arthur Kornberg

but this too was contaminated (He;) with trace metal. Impure
preparations must contain some protective factor, since our
impure preparations made via the !Yarburg technique were quite
stable.

We shall look forward to seeing your unravellinc of

the TPN structure.

Yours sincerely,

GAL : sek

G.A. LePage "
Assistant Frofessor of Oncology