Monitoring the production of biosynthetic human growth hormone by micro enzyme-linked immunosorbent assay

A micro enzyme-linked immunosorbent assay (e.l.i.s.a.) has been developed for monitoring the production of human growth hormone (hGH) in E. coli. The method is unusually flexible, as it is possible to modify its conditions to give a sensitive (detection limit 4 ng l^?1) or a fast (6 h) version. The assay is reproducible; the between-assay relative standard deviation is 6%. The effects of temperature, incubation time and the concentrations of protein and the most important reagents (the solid-phase antibody and the labelled antibody) are described. The utility of the method is demonstrated in experiments optimizing the conditions for production of hGH in E. coli.