A chondrogenic cell line derived from a differentiating culture of AT805 teratocarcinoma cells

Abstract A cell line, ATDC5, isolated from a differentiating culture of AT805 teratocarcinoma expressed a fibroblastic cell phenotype in a growing phase. With the addition of 10 μg/ml insulin to the medium, cells continued to grow even in a postconfluent phase, formed cartilage nodule-like cell aggregates, were stained with Alcian blue and produced cartilage-specific proteoglycan and type II collagen, typical marker molecules for chondrogenesis. Since ATDC5 cells also differentiated into unidentifiable pigmented cells, they are apparently composed of undetermined cells. ATDC5, therefore, provides a good model system with which to understand chondrogenic differentiation.