Naturally occurring soluble H-2 specificity in mouse tissues

Abstract

Liberation of radioactive chromium from labelled ascites tumour cells by mouse isoantiserum in the presence of complement has been used as a measure of cytotoxic H-2 antibody.

Specific inhibition of this reaction has been used to demonstrate the presence of substances carrying H-2 activity in saline extracts of normal and neoplastic tissues. The substances are not sedimented in 1 hour at 105,000 g, do not diffuse through dialysis tubing and are quantitatively precipitated between 25 and 50 per cent saturation with ammonium sulphate.