The international standard for epidermal growth factor (EGF): comparison of candidate preparations by in vitro bioassays and immunoassays. National Institute for Biological Standards and Control

Four preparations of recombinant human sequence epidermal growth factor (EGF), two of the full length 53-amino acid chain, and two of the 52-amino acid chain, lacking the carboxyl-terminal arginine, were evaluated, using a variety of in vitro bioassays and immunoassays, by 12 laboratories in seven countries, for their suitability to serve as the international standard for EGF. The study shows that some assay systems appear to discriminate between the full length and the 52-amino acid forms of EGF and that use of a common standard in place of the various in-house standards leads to a substantial decrease in between-laboratory variances in estimates of potency of EGF samples. On the basis of the results reported here, the World Health Organization (WHO) established one of the preparations of the full-length EGF molecule (coded 91/530) as the first international standard (IS) for EGF, with an assigned unitage of 2000 International Units/ampoule, and one of the preparations of EGF(1-52) (coded 91/550) as the first international reference reagent (IRR) for EGF (1-52) with a nominal mass content of 1.75 microg EGF(1-52)/ampoule. The IS for EGF and the IRR for EGF(1-52) may be obtained by writing to NIBSC, PO Box 1193, Potters Bar, EN6 3QH, UK.

Published by Growth factors (Chur, Switzerland), 1996. The guideline itself is at the source linked here.

doi.org/10.3109/08977199609003218