Isoelectric focusing of monoclonal antibodies by capillary electrophoresis.
The isoelectric points (pIs) of murine monoclonal antibodies (MAbs) determined by published one-step capillary isoelectric focusing (CIEF) methods using simultaneous focusing and electroosmotic mobilization showed appreciable deviation from the pI values determined by the slab gel electrophoretic method. The present report describes a modified one-step CIEF method that accurately determines the pIs of MAbs. The modifications include use of internal standards with pIs below and above the pI ranges of MAbs and calculation of pIs from a fitted nonlinear standard curve. Proteins with pIs in the same range as MAbs were first used to establish the efficacy of the method. The present CIEF procedure is highly reproducible and easy to perform for MAbs.
Kundu
S
S
Diagnostics Division, Abbott Laboratories, North Chicago, IL 60064, USA.
Fenters
C
C
D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000379:methods*; D007525:Isoelectric Focusing / Q000379:methods*; D051379:Mice
D000911:Antibodies, Monoclonal