title: Use of a quality-control plasma sample to decrease interassay variation in radioimmunoassays of apolipoprotein A-I.
abstract: The apolipoprotein A-I (apo A-I) radioimmunoassay established in our laboratory involves use of purified apo A-I as the primary standard for quantifying apo A-I in plasma and a pooled plasma (quality-control sample) as a secondary standard to decrease interassay variation. The measured values for apo A-I increased over time as the labeled antigen degraded. We observed these results in two separate studies: (a) apo A-I in plasma from 16 subjects was measured 12 times during four months, and (b) apo A-I in a single pooled plasma was measured 48 times during 10 months. We show that use of a quality-control plasma sample as a secondary standard decreased interassay variation, which was, in part, ascribable to degradation of the labeled antigen.
mesh_terms: D000328:Adult; D016632:Apolipoprotein A-I; D001054:Apolipoproteins A / Q000097:blood* / Q000592:standards; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D007553:Isotope Labeling; D008297:Male; D008875:Middle Aged; D011786:Quality Control; D011863:Radioimmunoassay / Q000379:methods; D012015:Reference Standards; D013223:Statistics as Topic
chemical_list: D016632:Apolipoprotein A-I; D001054:Apolipoproteins A; D007457:Iodine Radioisotopes