Retinol does not affect cell growth in fibroblast cell cultures

Retinol-free fetal calf serum for cell cultures was obtained by UV irradiation and by removal of retinol-binding protein (RBP) by gel-filtration. RBP from bovine serum was purified in a simple two-step procedure. This made it possible to replenish the culture medium with retinol in its physiological i.e. RBP-bound form. Retinol-free and retinol-containing medium was used to assay growth of 3T3 and L929 fibroblast cells. None of these cell lines showed a significant change in growth rate or saturation density that could be attributed to free or RBP-bound retinol.