Yolken R H, Stopa P J
J Clin Microbiol. 1979 Nov;10(5):703-7. doi: 10.1128/jcm.10.5.703-707.1979.
Solid-phase enzyme immunoassays can be utilized to detect antigens directly in clinical specimens. However, a small number of stools which we tested for human rotavirus by enzyme-linked immunosorbent assay (ELISA) were found to have nonspecific activity in the absence of rotaviral antigen. Similar nonspecific activity was found in eight of eight sera which contained rheumatoid factor. This nonspecific activity was markedly reduced by pretreatment of the specimens with reducing agents, normal goat serum, and anti-human immunoglobulin M (IgM). Thus, it is likely that these specimens contain an IgM antibody capable of reacting nonspecifically with the other components of the assay. Although pretreatment with the mild reducing agent N-acetylcysteine markedly reduced this nonspecific activity, such treatment did not reduce the specific ELISA activity due to rotavirus. Other treatments did produce a reduction in specific activity. Thus pretreatment with N-acetylcysteine offers a practical means to increase the specificity of ELISA systems without reducing their sensitivity.
固相酶免疫测定法可用于直接检测临床标本中的抗原。然而，我们通过酶联免疫吸附测定法（ELISA）检测人类轮状病毒的少数粪便样本，在不存在轮状病毒抗原的情况下发现有非特异性活性。在含有类风湿因子的8份血清样本中，有8份也发现了类似的非特异性活性。通过用还原剂、正常山羊血清和抗人免疫球蛋白M（IgM）对标本进行预处理，这种非特异性活性显著降低。因此，这些标本可能含有一种能够与检测分析的其他成分发生非特异性反应的IgM抗体。虽然用温和的还原剂N-乙酰半胱氨酸预处理可显著降低这种非特异性活性，但这种处理并未降低轮状病毒引起的特异性ELISA活性。其他处理确实会导致特异性活性降低。因此，用N-乙酰半胱氨酸预处理提供了一种切实可行的方法，可在不降低ELISA系统敏感性的情况下提高其特异性。
