Isolation of a cell line insensitive to growth-restricting action of dextran sulfate from 3t6 cells.

In the medium containing dextran sulfate, 3T6 cells stopped growth at almost monolayer stage and showed decreased saturation density. This action of dextran sulfate is referred to as a growth restriction. About 70% of untreated 3T6 cells formed piled-up colonies whereas the remaining 30% formed monolayer colonies. Fraction of the latter increased with increasing concentration of dextran sulfate in the medium. Cell lines sensitive and insensitive to the growth-restricting action of the compound were cloned from colonical culture of the wild type cells. Sensitive cells showed a slightly less saturation density than the wild type cells in the presence of dextran sulfate. Insensitive cells grown in dextran sulfate medium showed almost the same growth rate and saturation density as the untreated wild type cells grown in the absence of the compound.