title: Supplementary factors required for serum-free culture of rat kidney cells of line NRK-49F.
abstract: Factors required as supplements to basal tissue culture medium for the multiplication of cells of the cloned rat fibroblast line called normal rat kidney 49F (NRK-49F) were identified as epidermal growth factor, fibronectin, insulin, and retinoic acid. The requirement for fibronectin was manifested on a clean glass surface but not on the polystyrene plastic surface tested. This set of required factors differs substantially from the factor sets required by the Madin-Darby canine kidney (MDCK) and LLC-PK1 pig kidney lines of epithelial cells and the baby hamster kidney 21 (BHK-21) line of fibroblasts. The serum-free medium supplemented with the four factors supported rapid growth of NRK-49F cells when the initial cell population density was about 8,000 cells/cm2 or greater. At lower initial densities, cell multiplication was markedly increased by adding serum-free medium that had been conditioned by NRK-49F cells. Cell growth rate in the defined serum-free medium stayed high through two serial passages but declined in the third serial passage unless the cell-conditioned medium was added.
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002999:Clone Cells / Q000166:cytology; D003470:Culture Media; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology; D005353:Fibronectins / Q000494:pharmacology; D006133:Growth Substances / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology; D007668:Kidney / Q000166:cytology*; D051381:Rats; D014212:Tretinoin / Q000494:pharmacology
chemical_list: D003470:Culture Media; D005353:Fibronectins; D006133:Growth Substances; D007328:Insulin; D014212:Tretinoin; D004815:Epidermal Growth Factor