IDENTIFICATION OF ANTIGENIC DIFFERENCES OF RECOMBINANT AND PITUITARY BOVINE GROWTH-HORMONE USING MONOCLONAL-ANTIBODIES

For characterization and determination of recombinant bovine GH (rbGH) eight monoclonal antibodies (MAb) were produced against rbGH from Mon santo. The various MAb showed different affinities to rbGH, pituitary bovine GH (pbGH), and pituitary ovine GH (poGH). With epitope analysis several MAb were shown to recognize different epitopes of rbGH. The M Ab MUC-rbGH-3A11 and MUC-rbGH-1E5 were used to develop a Sandwich ELIS A. By checking the specificity of the assay no cross reactivity was fo und with pituitary porcine GH, pituitary human GH, bovine or ovine pro lactin and little cross reactivity with poGH could be found. The Sandw ich ELISA detected various rbGH (Monsanto, Elanco, Cyanamid) with diff erent N-terminal amino acids and discriminated between rbGH and pituit ary bovine GH by an affinity factor of 2.0. The detection level was 2 ng rbGH per mi PBS buffer. The recovery was about 86% in bovine serum. It might therefore be possible to detect rbGH-treated cows using a Sa ndwich ELISA, but this would need a field study.