Harris R B, Semar M, Johnson A J
J Lab Clin Med. 1977 Dec;90(6):1107-14.
A new method is described for the quantitative detection of HBsAg in whole human plasma and in plasma fractions. The nonantigen proteins are digested with pepsin at low pH, and the antigen is precipitated with PEG. With use of only 20 ml of contaminated plasma, as few as 5.0 x 10(6) HBsAg particles/ml can be detected--a 40-fold increase in the apparent level of sensitivity of the Ausria II RIA (2.0 x 10(8) particles/ml). With 500 500 ml or more of plasma or plasma fractions, fewer than 5.0 x 10(5) particles/ml can be assayed--a 400-fold increase in RIA sensitivity and 1/10 the antigen concentration found in sera that proved infective when injected into chimpanzees. The pepsin-PEG method was used to quantitate the particles per milliliter in four equivocal RIA samples from the NIH Bureau of Biologics, three of which were definitely shown to contain antigen. The method has also been employed to detect fewer than 2.0 x 1010(8) particles/ml of HBsAg in deliberately contaminated high purity AHF concentrates and may be useful for monitoring plasma fractions prepared on a large scale or for detecting the antigen in equivocal samples from blood banks.
本文描述了一种定量检测全人血浆及血浆组分中HBsAg的新方法。非抗原蛋白在低pH值条件下用胃蛋白酶消化，抗原用聚乙二醇沉淀。仅使用20ml污染血浆，就能检测到低至5.0×10⁶个HBsAg颗粒/ml，这比Ausria II放射免疫分析（RIA）的表观灵敏度水平（2.0×10⁸个颗粒/ml）提高了40倍。对于500ml或更多的血浆或血浆组分，可检测到低于5.0×10⁵个颗粒/ml，RIA灵敏度提高了400倍，且抗原浓度仅为注射到黑猩猩体内后证明具有感染性的血清中抗原浓度的1/10。胃蛋白酶 - 聚乙二醇法用于定量检测美国国立卫生研究院生物制品局的4份RIA结果不明确的样品中每毫升的颗粒数，其中3份明确显示含有抗原。该方法还用于检测故意污染的高纯度抗血友病因子浓缩物中低于2.0×10⁸个颗粒/ml的HBsAg，可能有助于监测大规模制备的血浆组分或检测血库中结果不明确样品中的抗原。
