Improved clonal growth of human solid tumors by isolation of viable cells

The potential for the establishment of predictive assays for cancer chemotherapy was generated recently by the development of a soft agar clonogenic assay for human tumor cells. Though the assay technique is promising, certain technical problems remain. One is the difficulty of preparing viable cell suspensions from solid human tumors. A method of separating viable and nonviable cells by Ficoll-Hypaque centrifugation was used. When this method was used to plate isolated viable single cells, an improvement in cloning was observed when compared with a nonseparated mixture of viable and nonviable cells.