摘要 |
A colony forming unit fibroblast (CFU-F) factor has been identified having the following characteristics: (a) it is a polypeptide present in P388 or 416B (ECACC provisional accession no. 94082401) cells and capable of extraction from the cell lysate or conditioned medium; (b) when added to explanted bone marrow adherent cells which are below the level capable of forming fibroblast colonies, it is capable of inducing the formation of fibroblast colonies; (c) it binds heparin-agarose at physiological pH; (d) the heparin binding fraction, when subjected to reducing SDS-PAGE, produces bands at about (12, 15, 16 and 17kD); (e) its activity is not affected by heating at 100 DEG C for 10 minutes; (f) it can be purified from the cell lysate by fractionation by anion-exchange chromatography, eluting at 0.3M sodium chloride; followed by size exclusion chromatography, optionally followed by further purification such as HPLC and/or SDS-PAGE. |