A practical approach to high performance capillary electrophoresis with biosynthetic human growth hormone as a model...

Biosynthetic human Growth Hormone (B-hGH) is a protein comprising 191 amino acids. The molecular weight is 22,125 and the isoelectric point is close to pH 5. Due to the ready availability of closely related analogues B-hGH was used as a model protein thus allowing for the demonstration and evaluation of the high resolution capability of high performance capillary electrophoresis (HPCE). The same apparatus was used throughout the experiments and an optimum signal-to-noise ratio was found at 200 nm. Linearity was observed between peak area, retention time and the hGH concentration or sample introduction time. Baseline separation of hGH, desamido hGH and didesamido hGH was obtained. Examples showing analysis with 1 million theoretical plates per meter, high speed separation, simultaneous analysis of multiple samples, sample stacking, hGH tryptic digest, and hGH lysate are reported. The use of electrophoretic velocities instead of apparent velocities for peak identification is illustrated.