Abstract
A new solid phase method of radioimmunoassay for LH has been developed utilizing easily obtainable inexpensive latex particles. Latex particles were coated with r-globulin from anti-HCG rabbit serum according to the method described previously by us (J. Clin. Endocrinol. 27 : 379, 1967) and recently some anti-HCG coated latex is available commercially. For urinary LH, the linear range of this assay method is from 3.0 to 60 IU/L (2nd IRP-HMG) using a commercially available anti-HCG coated latex (Gonavislide). This degree of sensitivity is obtained after only 20hr inculation at 20°C or 3 hr at 37°C in contrast to around a week required for the double antibody method. The effect of nonspecifiic substance in urine on LH titre was eliminated after purification of antiserum by means of absorption with peduex and separation of antibody by conjugation with polymerized HCG. The coefficient of variation is less than 10% on the linear portion of standard curve. Recovery experiment revealed that extraction of LH from urine is not necessary, as far as the method described is concerned.
Assay of LH in urine from menstruating women, prepuberal girls, postmenopausal women and normal adult males yielded the results similar to those reported in the past, thus providing additional evidence for the specificity of the method.
