Hirvonen M, Koskinen S, Tölö H
Finnish Red Cross Blood Transfusion Service, Helsinki, Finland.
J Immunol Methods. 1993 Jul 6;163(1):59-65. doi: 10.1016/0022-1759(93)90239-4.
A microtitre plate enzyme immunoassay (EIA) for determining low concentrations of IgA is described and validated for serum and plasma products. The measuring range of the assay was 3.3-150 micrograms/l. The predilution requirement of samples was matrix dependent, ranging from 1/16 for serum to 1/2 for 4% albumin. Dilute protein solutions required no predilution. The limits of detection were 50 micrograms/l for serum, 25 micrograms/l for intravenous immunoglobulin, 13 micrograms/l for 20% albumin, 7 micrograms/l for 4% albumin and 3 micrograms/l for washing solutions of blood cell components. Interassay coefficients of variation over the range of 3.4 mg to 1.5 g IgA/l ranged from 3.8 to 5.7%. Respective values for two low-level sera, containing 309 and 512 micrograms IgA/l, were 15.5% and 11.1%. Comparison of the EIA with a commercial radial immunodiffusion (RID) method showed that the results of the two assays correlated well ([EIA] = 0.877 x [RID] + 0.401 mg/l, r = 0.996, n = 20). This assay is also suitable for the large-scale screening of blood donors.
本文描述了一种用于测定低浓度IgA的微量滴定板酶免疫测定法（EIA），并对血清和血浆制品进行了验证。该测定法的测量范围为3.3 - 150微克/升。样品的预稀释要求取决于基质，血清的预稀释倍数为1/16，4%白蛋白的预稀释倍数为1/2。稀释的蛋白质溶液无需预稀释。血清的检测限为50微克/升，静脉注射免疫球蛋白为25微克/升，20%白蛋白为13微克/升，4%白蛋白为7微克/升，血细胞成分洗涤液为3微克/升。在3.4毫克至1.5克IgA/升范围内的批间变异系数为3.8%至5.7%。两份低水平血清（分别含309和512微克IgA/升）的相应值分别为15.5%和11.1%。将该EIA与商业径向免疫扩散法（RID）进行比较，结果表明两种测定法的结果相关性良好（[EIA] = 0.877×[RID] + 0.401毫克/升，r = 0.996，n = 20）。该测定法也适用于大规模筛查献血者。
