SEPARATION OF CELLS FROM MOUSE SOLID TUMORS BY CENTRIFUGAL ELUTRIATION

Abstract

Centrifugal elutriation was used to separate cells dissociated from 2 hypotetraploid mouse solid tumors, a fibrosarcoma and a sarcoma derived from L-P59 cells, based on their sedimentation rates. The separation was rapid, requiring less than 1 h, yielded about 80% cell recovery and resulted in little loss of cell viability. Analysis of DNA content by flow cytometry demonstrated the synchrony obtained with these tumor cells. The fractions with the lowest sedimentation rates contained predominantly normal cells, those with intermediate sedimentation rates contained predominantly tumor cells in the G1 phase of the cell cycle and those with the highest sedimentation rates contained mostly tumor cells in S or G2. The clonogenicity of L-P59 cells, assayed in culture, markedly increased with increasing sedimentation rates. The clonogenicity of fibrosarcoma cells, assayed in vivo by a lung colony assay, was lower for the smaller cells, but was essentially constant among the larger cells. Autoradiography of cells labeled in vivo with 3H thymidine demonstrated no differences in the proportions of cycling cells in various fractions. These results demonstrate that subpopulations differing in cell type, phase of the cell cycle and clonogenicity can be rapidly separated from solid tumors by centrifugal elutriation.