Comparative Studies with Chemotherapeutic Agents in Biologically Diverse in Vitro Cell Systems

Summary Simple procedures are described for the establishment and maintenance of continuous fluid mass cultures of mammalian cells, free-living nonparasitic protozoa, and nonfilamentous green algae, for laboratory use. These cultures served as production units to provide morphologically homologous but phylogenetically diverse organisms for use in large-scale drug testing. All these organisms were incorporated into agar-bioautograph systems, as well as into fluid cultures for turbidimetric studies with drugs of the antimicrobial and antitumor type. A comparative study was made in both fluid and agar systems utilizing the two mammalian cell strains—HeLa and NCTC 1742; the three protozoa— Euglena gracilis, Tetrahymena pyriformis and Ochromonas malhamensis ; and the green algae— Scenedesmus basiliensis and Chlorella vulgaris . The algae, Scenedesmus basiliensis , was the most sensitive organism studied. In agar systems the protozoa were superior to the mammalian cells in terms of detecting clinically useful cancer drugs, but less sensitive in terms of numbers of drugs detected. They were sensitive enough for mechanism of action studies. It is suggested that the nonparasitic protozoa in particular and protozoa and algae in general have not been thoroughly exploited for their potential use in industrial biological research.