An Examination of HeLa Cancer Cells for Production of Gamma-Globulin

Abstract

A METHOD has been described for detecting and measuring the autonomous production of well-defined proteins by cells in tissue culture^1,2. The method is exceedingly sensitive and is applicable even when the cells are cultivated in a ‘natural’ nutrient medium, that is, a medium also containing serum; such media have an enormous excess of pre-existing proteins. The tissue is incubated in presence of a radioactive amino-acid and the whole of the soluble protein is extracted. Thereafter individual proteins are isolated from the mixture and burnt, and the carbon dioxide obtained tested for radioactivity with a gas counter (efficiency nearly 100 per cent)^3,4. The identity of a fraction can be confirmed by treatment with specific antiserum, followed by determination of the distribution of the radiocarbon between precipitate and supernatant. Blank experiments show that after incubation of natural medium with radioactive amino-acid without cells practically no radiocarbon is found in protein.