[Screening of antineoplastic antibiotics using a rapid method of evaluating their cytostatic effect on tumor cells]

The study was aimed at development of a rapid method for estimating in vitro cytostatic action of antitumor antibiotics on the basis of intensity of inclusion of labeled precursors into nucleic acids of tumor cells which should be useful in primary screening of antibiotics with potential antitumor activity. The method was applied to substances isolated from 600 cultures of actinomycetes. 35 antibiotics showed antitumor activity; 8 of them were studied in detail. They proved to be novel antibiotics having antitumor activity in animals.