NONRADIOACTIVE IMMUNOASSAYS IN TOXICOLOGY - INSTRUMENTATION AND ANALYSIS OF HORMONES

We have designed and executed comparative studies with the objective o f selecting instrumentation for the non-isotope immunological determin ation of free and total thyroxine (fT4 and tT4), and total triiodothyr onine (tT3) and progesterone in rat plasma for general toxicity studie s. In addition, this instrumentation has been used for the determinati on of progesterone in rabbits for early pregnancy diagnosis in reproto xicity studies. During instrument selection, special emphasis has been given to automation and on-line coupling capabilities, maximal flexib ility in method development, walkaway capability, manufacturers' compu ter validation and GLP performance, linearity and intra-assay CV. For tT3 and tT4, seven instruments have been compared with each other wher eas for progesterone and fT4, three instruments were compared. Normal rat plasma values have been subjected to variance analysis, followed b y Duncan testing. The instrument selection process finally indicated t he ES300 Enzymun ELISA of Boehringer Mannheim as the best candidate on the aspects defined above. Spiking recovery values on the ES300 are p resented. The ES300 provides a reliable pregnancy diagnosis for rabbit s as early as day +4 after mating in the predosing period.