Barlough J E, Jacobson R H, Downing D R, Marcella K L, Lynch T J, Scott F W
J Clin Microbiol. 1983 Feb;17(2):202-17. doi: 10.1128/jcm.17.2.202-217.1983.
A computer-assisted, kinetics-based enzyme-linked immunosorbent assay was adapted for the detection of coronavirus antibodies in feline serum. An alkaline antigen diluent (carbonate-bicarbonate buffer, pH 9.6) used in initial experiments produced diffuse, nonspecific color reactions in both viral and control antigen cuvettes which were correlated, paradoxically, with coronavirus antibody levels in test sera. These interfering reactions were minimized by use of lower-pH antigen diluents such as water and phosphate-buffered saline. Background kinetics-based enzyme-linked immunosorbent assay reactivity directed against a noncoronaviral component of antigen tissue culture fluids could then detected in numerous sera, particularly in samples with lower titers. Much of this reactivity was shown to be associated with bovine gamma globulins in cell culture fluid. It was not serum lot or species specific, since a variety of bovine serum lots as well as individual lots of serum from other mammalian and avian species reacted. Reactivity was markedly reduced when cells for antigen preparation were grown in gamma globulin-free bovine serum. Generation of corrected slope values from the kinetics-based enzyme-linked immunosorbent assay made it possible to correct for residual background reactivity in individual test sera and thus eliminate a potentially major source of false-positive reactions. Collectively, these studies indicated that the control of nonspecific reactivity in feline coronavirus serology is absolutely essential to obtain useful estimates of specific antibody responses.
一种基于动力学的计算机辅助酶联免疫吸附测定法被用于检测猫血清中的冠状病毒抗体。在初始实验中使用的碱性抗原稀释液（碳酸盐 - 碳酸氢盐缓冲液，pH 9.6）在病毒抗原比色皿和对照抗原比色皿中均产生弥漫性、非特异性颜色反应，奇怪的是，这些反应与测试血清中的冠状病毒抗体水平相关。通过使用较低pH值的抗原稀释液，如水和磷酸盐缓冲盐水，可将这些干扰反应降至最低。基于动力学的酶联免疫吸附测定法针对抗原组织培养液中非冠状病毒成分的背景反应性，随后在众多血清中被检测到，特别是在滴度较低的样本中。结果表明，这种反应性大多与细胞培养液中的牛γ球蛋白有关。它不是血清批次或物种特异性的，因为多种牛血清批次以及来自其他哺乳动物和鸟类物种的个别血清批次都有反应。当用于制备抗原的细胞在无γ球蛋白的牛血清中生长时，反应性明显降低。基于动力学的酶联免疫吸附测定法生成校正斜率值，使得校正个别测试血清中的残留背景反应性成为可能，从而消除了潜在的主要假阳性反应来源。总体而言，这些研究表明，在猫冠状病毒血清学中控制非特异性反应性对于获得特异性抗体反应的有用估计绝对至关重要。
