A Cytochemical Section-bioassay for Thyrotropin

Abstract

A cytochemical section-bioassay of thyrotropin has been developed which retains the sensitivity of the earlier segment-assay (10⁻⁴ μU/ml) and allows a considerable increase in the rate at which these within-animal bioassays can be done. The index of precision (n=23) was 0.11 ± 0.06; intra-assay variation was 1.3%; inter-assay variation was 10.9 ± 6%. Fiducial limits (p=0.95) ranged from 65–150% to 78–127%. The system is also capable of detecting thyroid-stimulating immunoglobulins.