Celada F, Natali P G, Radojkovic J
J Immunol. 1976 Sep;117(3):904-10.
A method for detection of the primary binding of soluble tumor-associated antigens by antibodies has been developed by using an enzyme immunoassay (EIA). A heteroantiserum was produced by injecting tumor cells from a chemically induced murine sarcoma into rabbits, and antibodies reacting with most normal tissue components were removed by exhaustive in vivo absorption. A soluble preparation of tumor cells, obtained by 3 M KCl extraction, was conjugated to beta-galactosidase from Escherichia coli. The antibody binding was measured by determining the enzyme activity that could be separated by anti-antibody coprecepitation. The reaction follows saturation kinetics, and nonlabeled antigen can be readily quantitated by inhibition. The present method detects determinants common to several MC-induced tumors on the same mouse strain but absent in normal cells and nonrelated tumors in addition to individual tumor-specific transplantation antigens. The sensitivity and simplicity of the new method compare favorably with a binding assay that utilizes radioactive iodine as a label. Thus, EIA becomes a flexible tool for the further characterization and purification of these antigens.
通过使用酶免疫测定法（EIA），已开发出一种检测抗体与可溶性肿瘤相关抗原的主要结合的方法。通过将化学诱导的小鼠肉瘤的肿瘤细胞注射到兔子体内产生异种抗血清，并通过体内彻底吸收去除与大多数正常组织成分反应的抗体。通过3M KCl提取获得的肿瘤细胞可溶性制剂与来自大肠杆菌的β-半乳糖苷酶偶联。通过测定可通过抗抗体共沉淀分离的酶活性来测量抗体结合。该反应遵循饱和动力学，并且未标记的抗原可以通过抑制作用容易地定量。本方法检测同一小鼠品系上几种MC诱导肿瘤共有的决定簇，这些决定簇在正常细胞和无关肿瘤中不存在，此外还有个体肿瘤特异性移植抗原。新方法的灵敏度和简便性与利用放射性碘作为标记的结合测定法相比具有优势。因此，EIA成为进一步表征和纯化这些抗原的灵活工具。
