Identification of Transformed Liver Cell Colonies Using Concanavalin A Attached to Agarose Beads1

A method for the in vitro identification of transformed rat liver epithelial and hepatoma cells was developed using the prefer ential 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 in creased attachment of Con Aiagarose to cell colonies is a characteristic of transformed or malignant rat liver cells.