Monoclonal-antibody-based enzyme-linked immunosorbent assay for HMG 2b nonhistone protein in chick liver

Monoclonal antibodies were prepared against the high mobility group (HMG) protein 2b from chick liver chromatin and a monoclonal-antibody-based enzyme-linked immunosorbent assay (ELISA) was developed for chick HMG 2b. The sensitivity of the assay is about ten times that of the previously described radioimmunoassay and solid-phase enzyme immunoassay for HMG proteins. With the use of ELISA technique, the amount of HMG 2b (micrograms protein/mg DNA) in the livers of 1-day old and 70-day old chicks was found to be 2.56 +/- 0.4, and 1.20 +/- 0.2, respectively. The age-dependent change in the level of HMG proteins probably reflects changes in the functional state of chromatin during ageing.