用单克隆抗体检测患者血清、粪便、胃液、胸腹水中肿瘤相关抗原,已做为肿瘤诊断的一种辅助手段。影响诊断精度的关键之一是抗原的纯度。经常采用的亲和层析法比凝胶层析法和电泳法纯化的抗原纯度高,但因其得率少易失活,有时不能满足实验需求,对于提供临床试剂盒的应用有一定困难,有必要寻找一个既简单,得率又较高、抗原又不易失活的分离抗原的方法。本文采用CsCl等密度离心法从结肠癌组织匀浆液中提取肿瘤相关抗原。它利用测定颗粒漂浮密度静力学的方法将复杂的肿瘤 Monoclonal antibody detection of serum, feces, gastric juice, pleural and ascites tumor-associated antigens, as an adjunct to the diagnosis of cancer. One of the keys to the accuracy of the diagnosis is the purity of the antigen. Often used affinity chromatography than gel chromatography and electrophoresis purification of antigen purity, but because of its low yield and easy to inactivation, and sometimes can not meet the experimental needs for the application of clinical kit has some difficulties, There is a need to find a simple, high-yielding, antigen-independent method for the isolation of antigens. In this paper, CsCl and other methods of density centrifugation from colon cancer tissue homogenate extracted tumor-associated antigen. It uses a method of determining the particle floating density statics of complex tumors