TISSUE CULTURE STUDIES

Abstract

Comparison of the content of ribonucleic and desoxyribonucleic acids in cultures of embryonic chick heart fragments in various culture media showed that horse serum led to greater loss of both constituents than did embryo extract, or than a complete medium containing both constituents. Embryo extract alone was little, if any, inferior to the complete medium. Similar but more striking results were obtained by measuring the synthesis of the nucleic acids by means of incorporation of p32. The total uptake of tracer P by the culture was highest with complete medium and very low with horse serum. Cutting of the heart into very small fragments increased very greatly all of the effects studied as compared with the same weight of tissue in larger pieces.