The World Health Organization reference reagent for keratinocyte growth factor, KGF

Preparations of human sequence recombinant keratinocyte growth factor (KGF), fibroblast growth factor-7 (FGF-7) synthesized in E. coli were formulated and lyophilized at National Institute for Biological Standards and Control (NIBSC) and evaluated in a collaborative study using in vitro bioassays and immunoassays. One candidate standard was the full-length mature KGF molecule and the two others were different formulations of a truncated form of the molecule, KGF (24-163). The study demonstrated the difficulty of performing interlaboratory comparison of assays without a common reference standard and differences in dose-response relationships between molecular variants. On the basis of the results reported here, the World Health Organization (WHO) established the preparation coded 03/150 as the WHO reference reagent for human KGF, with an assigned unitage of 4000 units of KGF per ampoule and the preparation coded 03/148 as the WHO reference reagent for human KGF (24-163), with an assigned unitage of 9000 units of KGF(24-163) per ampoule.