EVALUATION OF ASSAY DESIGNS FOR ASSAYS USING MICROTITRE PLATES - RESULTS OF A STUDY OF IN-VITRO BIOASSAYS AND IMMUNOASSAYS FOR TUMOR-NECROSIS-FACTOR (TNF)

Biological assays for tumour necrosis factor (TNF) are primarily based on its cytotoxic effect in tumour cell lines, and many of these bioas says are carried out using microtitre plates. Many immunoassays for TN F also routinely use microtitre plates. Data from an international col laborative study, carried out by twenty participants in nine countries , each of whom evaluated seven different ampouled preparations of huma n tumour necrosis factor alpha (hTNF-alpha), one ampouled preparation of human tumour necrosis beta (hTNF-beta) and one ampouled preparation of mouse tumour necrosis factor alpha (mTNF-alpha) provided a unique opportunity for a broadly based evaluation and comparison of assay des igns and results. The results of this evaluation can be applied to a w ide range of in vitro assays based on cell cytotoxicity or proliferati on. The results of this evaluation indicated that although it is diffi cult to achieve control of all factors which contribute to the variabi lity of assay responses, assays may be designed to provide measures of the variation due to some factors and to improve reliability of estim ates of relative potency. (C) 1995 The International Association of Bi ological Standardization