Analysis of mouse, rat, dog, marmoset, and human serum proteins by capillary electrophoresis: comparison with agarose gel electrophoresis

Background: Serum protein analysis in both humans and experimental animal species has so far been carried out by labor-intensive techniques, such as agarose gel electrophoresis (AGE). Objective: The objective of this study was to evaluate capillary electrophoresis (CE) as an alternative technique to AGE for the analysis of serum proteins from healthy animals. Methods: Blood samples were collected into tubes without anticoagulant from 6 fasted healthy male mice, rats, dogs, marmosets, and humans. Serum proteins were separated by CE using a technique standardized for the analysis of human proteins, and the results (efficiency, resolution, and precision) were compared with those obtained through AGE. Results: Compared with AGE, CE resulted in narrower peaks and more peaks. The efficiency of protein separation by CE was significantly higher for all species, and resolution (R) was significantly higher in samples from dogs. Using rat serum, intraday reproducibility was lower for all protein fractions, and interday reproducibility was lower for most peaks, compared with AGE. Conclusions: We conclude that CE is a viable alternative to AGE for the determination of protein electrophoresis in a routine veterinary clinical pathology laboratory. The minimal sample requirement (2 μL), complete automation, and quantitative results make CE an especially valuable technique for protein analysis in experimental animal models.