基于磁性微球的免疫荧光法对癌胚抗原的检测

Determination of Carcinoembryonic Antigen Based on Magnetic Microsphere Assited Fluoroimmunoassay

采用双夹心磁性微球免疫荧光显微法对样品中的癌胚抗原进行分离与检测。首先用EDC/NHS对磁性微球表面的羧基进行活化后偶联抗癌胚抗原单克隆抗体m Ab CEA-C3制成免疫磁珠,再对样品中的CEA进行捕获,并进行免疫标记,最后用荧光显微镜进行检测。考察洗涤次数和免疫时间等因素对实验的影响,在最优条件下对CEA进行检测,结果表明:随着CEA浓度的增加荧光强度逐渐增强,检测限为9.67 ng/m L,可实现对CEA的定性和半定量测定。该方法操作简单快捷,样品用量少,选择性好,可应用于临床检验。

A novel immunoassay for the determination of CEA was established by combining a fluoroimmunoassay and immunomagnetic separation. Carboxyl groups on the magnetic beads were first activated with a mixture of EDC and NHS to give reactive succinimide esters. The m Ab CEA-C3 was then passed over the surface and esters react spontaneously with amino groups to link m Ab CEAC3 covalently to magnetic beads to form Immonumagnetic beads（IBMs）. In the mixture samples, CEA was captured by m Ab CEA-C3 with high specificity and affinity. The conditions, such as washing times and immune reaction time were optimized. The final choice of immune time is 45 min, three times of washing. The results indicated that the fluorescence intensity increased with the increment of CEA concentration in the optimal condition. The LOD is 9.67 ng/m L. Qualitative and semiquantitative detection of CEA was conducted based on the combination of IBMs with fluoroimmunoassay. The method is simple and sensitive and could be a possible application for the detection of CEA in clinical diagnostics.