August 17, 1943
Dr. Robert Loeb
College of Physicians and Surgeons
620 West 168th Street
New York, New York
Dear Dr. Loeb:
Today Dr. Campbell and I had the pleasure of a visit from Dr. Gregersen, who probably was steered this way by you. We have had an interesting discussion with him.
A few days ago we sent several samples of our preparations of oxypolygel to Dr. Luck. Today a letter came from him, in which he says that he is not able to carry on any molecular weight determinations, and that he does not have a centrifuge with which to do the work.
I feel that studies with the ultracentrifuge are needed, and I hope that you will tell me that it would be all right for us to send a number of samples to Williams or to Cohn's laboratory. We sent a couple of samples to Williams, and received a brief report on one of them.
It looks as though our method of preparation is not well enough standardized to give a uniform product—the osmotic pressure varies from preparation to preparation. With some evidence from the ultracentrifuge as to how the distribution in molecular weight is changing, we should be able to improve the method.
With best regards, I am
Sincerely yours,
Linus Pauling
LP:jr
cc D. H. Campbell
August
17, 1943
