A BIOLOGICAL METHOD FOR THE QUANTITATIVE MEASUREMENT OF TETRODOTOXIN (TTX) - TISSUE-CULTURE BIOASSAY IN COMBINATION WITH A WATER-SOLUBLE TETRAZOLIUM SALT

A tissue culture bioassay, using the mouse neuroblastoma cell line (Ne uro2A), was improved to provide a simple and sensitive bioassay for TT X or sodium channel-blocking toxins (SCB). The water-soluble tetrazoli um salt, 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2, 4-disulfophenyl)-2H- tetrazolium, monosodium salt (WST-1), was applied to replace the time- consuming and subjective cell-counting procedure of the cells with aut omatic measurement, using a microplate reader. It was also confirmed t hat this method is directly applicable to bacterial culture supernatan ts, with the precaution of possible interference. (C) 1996 Elsevier Sc ience Ltd.