Abstract: | The effects of aggregation, retinoic acid, and medium conditioned by Buffalo rat liver (BRL) cells, alone and in combination, on the differentiation of PSA4TG12 embryonal carcinoma and E14 embryonal stem cells are reported. The observations indicate that BRL-conditioned medium has more than one effect on the differentiation process, that retinoic acid has at least two effects which operate in different concentration ranges, and that both agents influence the choice of differentiation pathway as well as the extent of differentiation. |