The Milk Agent in Spontaneous Mammary Carcinoma

Abstract

Spontaneous or transplant tumor tissue was homogenized in water, buffers or saline soln. and then either lyophilized or centrifuged and the supernatant treated in various ways. Test animals to be inj. with the various fractions were between 4-10 wks. old and were hybrids between C57 black $? and A strain $$ or the back-cross mice from these hybrids to A c?o. A few fostered C3H and A strains were used.The expts. showed that the milk agent is destroyed at 60[degree]or higher, that it is stable at pHs 5.0-10.2 but not at pH 4.5, that it is not inactivated by petroleum, ether or acetone nor appreciably soluble in them, and that it is partially precipitated by salmine at pHs 5.5 and 6.8.