[Subtyping of Pi in human bloodstains by isoelectric focusing]

Subtyping of Pi (alpha 1-AT) in 90 human bloodstains stored under different conditions was carried out by using ULPAGIF. The detectable time of Pi subtypes of all bloodstains kept at room temperature (12-20 degrees C), 4 degrees C and-15 degrees C was 10 days, 4 weeks and 4 weeks respectively. Beyond this time limit, the detectable rate decreased gradually. The minimal detectable quantity, of fresh bloodstains was 4 microliters. The factors influencing the detection of Pi subtypes in bloodstains were discussed.