Subtyping of group-specific component and protease inhibitor by rapid isoelectric focusing on PhastSystem.

A rapid method on PhastSystem was used to investigate the distribution of group-specific component (GC) and protease inhibitor (PI) subtypes and their gene frequencies from 190 unrelated healthy donors of the Han population in Beijing. Laboratory-made gels (pH 4.5-5.4 and pH 4.2-4.9) were used for analysis of GC and PI, respectively. Sample loading was 1.5 microliters. The separation and visualization time was 0.5 h in each. Gene frequencies were as follows: GC1F = 0.4891, GC1S = 0.2432, GC2 = 0.2678; rare GC variants were discovered in seven cases. The results for PI were: PIM1 = 0.7542, PIM2 = 0.1808, PMM3 = 0.0650. Good agreement between the observed and expected values in both GC and PI subtyping (for GC, sigma chi 2 = 1.4043, 0.7 < P < 0.8; for PI, sigma chi 2 = 1.1233, 0.7 < P < 0.8) was obtained.