A sandwich enzyme immunoassay of human growth hormone in serum using anti-human growth hormone IgG-beta-D-galactosidase conjugate.

A sandwich enzyme immunoassay for the measurement of human growth hormone in serum was developed using antibody IgG-beta-D-galactosidase conjugate and antibody IgG-coated silicone rubber rods. The sensitivity of the assay was 4 pg/tube, which corresponded to 0.4 ng/ml, when 10 microliters of serum was used. The assay system showed little cross-reaction to other human pituitary hormones including prolactin, thyroid-stimulating, follicle-stimulating and luteinizing hormones and human chorionic gonadotropin. The coefficients of variation for different levels of serum hGH ranged from 5.8-9.3% and 6.7-14.5%, for within and between run, respectively. The regression equation and coefficient for correlation to radioimmunoassay were gamma (EIA) = 1.06 kappa (RIA) -0.22 and 0.97 (n = 46), respectively.