SEPARATION OF RECOMBINANT HUMAN GROWTH-HORMONE FROM ESCHERICHIA-COLI CELL PELLET EXTRACT BY CAPILLARY ZONE ELECTROPHORESIS

Free zone capillary electrophoresis (FZCE) was used to resolve recombi nant human growth hormone (rhGH) and its variants from very crude mixt ures of Escherichia coli (E. coli) cell paste extract. The methodology employs a phosphate deactivated fused-silica capillary and a 250 mM p hosphate (pH 6.8), 1% (v/v) propylene glycol buffer with a high field strength of 600 V/cm. Resolution of rhGH and its variants from very cr ude mixtures did not change after 80 injections for the PSC capillarie s. Bare silica and PVA coated capillaries had a more limited lifetime when injected with the same crude mixtures (10 to 30 injections). This FZC method provides a very powerful tool for assessing rhGH modificat ion during the fermentation and isolation of rhGH that is not possible with other current analytical techniques.