本文建立了一种用同位素~(125)I标记免疫复合物(IC)的方法,来测定IC中抗原和抗体的性质。作者用含有金黄色葡葡菌的滤器,从黑色素瘤病人血浆中吸附IC,然后用Mgcl_2将IC等洗脱下来。分离的物质用PEG沉淀法进行纯化,再用~(125)I将IC进行标记。~(125)I标记了的抗原和抗体的复合物在pH2.6时解离,蔗糖密度梯度超速离心,将抗原和抗体分离。发现放射活性的70％存在于梯度的上1/3。分别将上1/3和2/3部分的两种物质中和。用同位素计数的方法可以证明其中上1/3部分可与自身的IgG重新结合; In this paper, we established a method of labeling immunocomplexes (ICs) with isotope 125 I to determine the properties of antigens and antibodies in ICs. The authors used a filter containing S. aureus to adsorb IC from the plasma of melanoma patients and then eluted the IC using MgCl2. The isolated material was purified by PEG precipitation and the IC tagged with ~ (125) I. The complex of ~ (125) I-labeled antigen and antibody was dissociated at pH 2.6 and sucrose density gradient was ultracentrifuged to separate antigen and antibody. 70% of the radioactivity was found to be in the upper third of the gradient. Respectively, on the 1/3 and 2/3 part of the two substances and. With isotope counting method can prove that the upper 1/3 part of its own IgG re-binding;