Determination of alpha 1-antitrypsin in fecal extracts by enzyme immunoassay.
An enzyme immunoassay (EIA) has been developed for the determination of alpha 1-antitrypsin (AT). The assay can measure AT in fecal extracts (0.2 g wet feces/ml) from all healthy individuals. Purified human AT was coupled to peroxidase by means of a heterobifunctional reagent and the conjugate was used as a labeled antigen in competitive immunoassays. Concentrations of AT in feces from healthy individuals were less than 0.55 mg/g wet weight or less than 2.2 mg/g dry weight. CV for the physiological day-to-day variance varied between 9 and 140%. After incubation for 48 h at 37 degrees C, the average recovery rates for AT were 78% in ileostomy fluids, 88% in fecal extracts and 92% in feces. Results obtained with EIA correlated well with those obtained with a commercial radial immunodiffusion assay (r = 0.95).
Diagnostic Centre SSDZ, Delft, The Netherlands.
J
J
Brouwer
F
F
Smekens
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D002848:Chromatography, DEAE-Cellulose; D005243:Feces / Q000032:analysis*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D013056:Spectrophotometry, Ultraviolet; D000515:alpha 1-Antitrypsin / Q000032:analysis*
D000515:alpha 1-Antitrypsin