Radioimmunoassay of bovine, ovine and porcine luteinizing hormone with a monoclonal antibody and a human tracer.
A radioimmunoassay for bovine (bLH), ovine (oLH) and porcine (pLH) luteinizing hormone was developed using a human 125ILH tracer from a commercial kit and a monoclonal antibody (518B7) specific for LH but with low species specificity. Standard curves demonstrated similar binding kinetics when bLH, oLH and pLH were incubated with tracer and antibody for 2 h at room temperature. A 30-min delay in the addition of the tracer gave sufficient sensitivity when analysing pLH. Separation of antibody-bound LH from free hormone was achieved by using second antibody-coated micro Sepharose beads. The assay was validated and the performance compared with that of an RIA currently in use for determination of bLH and oLH (coefficient of correlation: 0.99 and 0.98). Regardless of the standards used, intra-assay coefficients of variation were < 10% for LH concentrations exceeding 1 microgram/L. The inter-assay coefficients of variation were < 15%. The assay was used for clinical evaluation demonstrating the pre-ovulatory LH surge in two cyclic cows, LH pulsatility in an oophorectomized ewe and LH response to GnRH injection in a boar.
Forsberg
M
M
Department of Clinical Chemistry, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala.
Tagle
R
R
Madej
A
A
Molina
J R
JR
Carlsson
M A
MA
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D015415:Biomarkers; D002417:Cattle / Q000276:immunology*; D005260:Female; D006801:Humans; D007986:Luteinizing Hormone / Q000276:immunology*; D008297:Male; D011863:Radioimmunoassay / Q000662:veterinary*; D012015:Reference Standards; D012756:Sheep / Q000276:immunology*; D013552:Swine / Q000276:immunology*
D000911:Antibodies, Monoclonal; D015415:Biomarkers; D007986:Luteinizing Hormone