To: Dr. Pauling From: R. A. Pasternak Date: February 15, 1954
Subject: Collagen
As a result of a discussion with Dr. Corey and Dr. Schroeder I propose to carry on
the following experiments in order to correlate the density, unit cell dimensions,
and the chemical composition of a given sample of collagen:
A uniform piece of raw kangaroo tendon is swollen in water and split along the fiber
axis. The one half is shredded finely to average out possible variations in composition
and used for chemical analysis. The other half, which is reserved for the physical
experiments, is slightly stretched to get a straight sample. Both samples are dried
to constant weight over a saturated solution of K2C03 (relative humidity 44% at room
temperature). The shredded sample will be sent away for a duplicate analysis of C,
H, N, and of loosely bound water. The other sample will be photographed in the 10
cm. camera again over a saturated K2C03 solution, finally the density of this sample
will be determined by floatation.
R. A. Pasternak
