Establishment of a reference ELISA for measurement of universal thresholds of pregnanediol glucuronide excretion rates using urine samples diluted to a constant volume per unit time.

Establishment of a reference ELISA for measurement of universal thresholds of pregnanediol glucuronide excretion rates using urine samples diluted to a constant volume per unit time. J Immunoassay Immunochem. 2016 Sep 16; Authors: Binnie JE, Cooke DG, Blackwell LF Abstract An enzyme linked immunosorbent assay (ELISA) for measurement of pregnanediol-3α-glucuronide (PdG) excretion rates in urine samples diluted to 150 mL/h before analysis is described. The sensitivity of the 9 optimized standard curves was 0.093±0.070 μmol PdG/24 h, with the multiple combined standard curves having a mean mid-point (EC50) of 6.88 μmol PdG/24 h. The PdG threshold excretion rate of 7.0 μmol/24 h,which is used as a marker for the end of fertility, was situated in the most accurate region of the standard curve. The specificity of the ELISA was determined using normal variate transformation to compare seven menstrual cycle profiles obtained with the ELISA method with the profiles obtained previously using a validated radioimmunoassay (RIA) method. The cycle profiles all agreed within experimental error, and a high degree of correlation using Deming regression was obtained. The correlation equation was Y=1.57X-0.11 μmol PdG/24 h (n=200; r=0.932). The PdG excretion rates determined by the ELISA were 50% higher than given by RIA, but the normal ranges were similar to those given by the original reference gas liquid chromatographic method. The ELISA assay...
Source: Journal of Immunoassay and Immunochemistry - Category: Biochemistry Tags: J Immunoassay Immunochem Source Type: research