The plasma proteins of C3H mice bearing spontaneous mammary adenocarcinoma were fractionated by zone electrophoresis on cornstarch gel stiffened by additional amylose, and rabbits were immunized with purified protein fractions. Precipitin reactions by the agar gel diffusion technic clearly demonstrated the presence of an anomalous protein in the plasma of tumor-bearing mice which is absent in normal control animals. Differences in concentration of certain proteins, in particular of α-globulins, between the plasma of normal and of tumor-bearing animals were also evident.

In 34 out of 37 instances, tumor-bearing animals were correctly identified by the observation of an extra precipitin line, whereas 6.5 per cent of the observations were doubtful and only 1.5 per cent were incorrect. With another rabbit antiserum, producing a weaker extra line, 74 per cent correct, 14 per cent doubtful, and 12 per cent incorrect observations were obtained. The significance of these data lies in the potentiality of this procedure as a diagnostic tool.

*

Supported in part by research grant C-3852 from the National Cancer Institute, National Institutes of Health, U.S. Public Health Service, and by a gift from Maurice Gordon, Boston, Massachusetts.

This content is only available via PDF.