Identification of transformed liver cell colonies using concanavalin A attached to agarose beads

A method for the in vitro identification of transformed rat liver epithelial and hepatoma cells was developed using the preferential microagglutination of concanavalin A (Con A) coupled to agarose beads (Con A:agarose) to their colonies. Con A:agarose attaches to the cell surface through a specific interaction of the Con A moiety and its receptors. The attachment is dependent on the mobility and aggregation of the Con A: receptor complex on the membrane. Agents which interfere with the interaction reduced the bead density over the colonies. For the quantitative determination of transformed colonies in a mixed-cell population, also containing untransformed cells, it is essential to compare colonies of a similar size or to use the bead density per unit area as the index. When a variety of rat liver epithelial cell lines were tested, the assay proved to be simple, reproducible, and precise. It was found that the increased attachment of Con A:agarose to cell colonies is a characteristic of transformed or malignant rat liver cells.