Cinemicrographic Analysis of Cell Populations In Vitro

With low magnification time-lapse cinemicrography we explored some of the dynamic morphologic and behavioral features of cell populations in vitro suitable for use in the characterization and comparison of cell strains. Three cell lines having a common single cell origin but different nutritional histories were used: clone strain NCTC 929, maintained in chick-embryo extract-horse serum medium; strain NCTC 2071, a line of strain 929 adapted to long-term growth in chemically de-fined, protein-free medium NCTC 109; and strain NCTC 3500, a line of strain 2071 that was returned to chick-embryo extract-horse serum medium. Certain striking changes in cell appearance and activity resulted from the adaptation of the cell strain from the protein-containing medium to the chemically defined medium. These included marked changes in cell morphology, reduction of intercellular cohesion, increased adhesiveness of cells to the glass substrate, and resultant greatly decreased cell migration. Such changes apparently were not primarily the result of cell selection inasmuch as the characteristics of cells of the line returned to the protein medium tended to revert to those of the original strain. The results emphasize the importance of the influence of the nutritional environment on the appearance and activity of cells. Technical difficulties in the use of cinemicrography for determination of rates of cell proliferation and population increase are considdered.