Pan Li, Zhao Jingjin, Huang Yong, Zhao Shulin, Liu Yi-Ming
Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education), College of Chemistry and Pharmacy, Guangxi Normal University, Guilin 541004, China; Department of Chemistry and Biochemistry, Jackson State University, 1400 Lynch St., Jackson, MS 39217, USA.
Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education), College of Chemistry and Pharmacy, Guangxi Normal University, Guilin 541004, China.
Clin Chim Acta. 2015 Oct 23;450:304-9. doi: 10.1016/j.cca.2015.09.002. Epub 2015 Sep 3.
Carcinoembryonic antigen (CEA) as one of the most widely used tumor markers is used in the clinical diagnosis of colorectal, pancreatic, gastric, and cervical carcinomas. We developed an aptamer-based microchip electrophoresis assay technique for assaying CEA in human serum for cancer diagnosis.
The magnetic beads (MBs) are employed as carriers of double strand DNA that is formed by an aptamer of the target and a complementary DNA of the aptamer. After the aptamer in the MB-dsDNA conjugate binds with the target, the complementary DNA was released from the MB-dsDNA conjugate. The released complementary DNA hybridizes with a fluorescein amidite (FAM) labeled DNA, and forms a DNA duplex, which triggers the selective cleavage of FAM labeled DNA by nicking endonuclease Nb.BbvCI, and generating a FAM labeled DNA segment. The released complementary DNA hybridizes with another FAM labeled DNA, resulting in a continuous cleavage of FAM labeled DNA, and the generation of large numbers of FAM labeled DNA segments. In MCE laser induced fluorescence detection (LIF), the FAM labeled DNA segment is separated and detected.
The linear range for CEA was 130 pg/ml-8.0 ng/ml with a correlation coefficient of 0.9916 and a detection limit of 68 pg/ml. The CEA concentration in the serum samples from healthy subjects was found to be in the range 1.3 ng/ml to 3.2 ng/ml. The CEA concentration in the samples from cancer patients was found to be >15 ng/ml.
This method may become a useful tool for rapid analysis of CEA and other tumor markers in biomedical analysis and clinical diagnosis.
癌胚抗原（CEA）作为应用最为广泛的肿瘤标志物之一，用于结直肠癌、胰腺癌、胃癌和宫颈癌的临床诊断。我们开发了一种基于适配体的微芯片电泳检测技术，用于检测人血清中的CEA以辅助癌症诊断。
磁珠（MBs）用作双链DNA的载体，双链DNA由靶标的适配体及其互补DNA形成。当MB - dsDNA偶联物中的适配体与靶标结合后，互补DNA从MB - dsDNA偶联物中释放出来。释放出的互补DNA与荧光素亚磷酰胺（FAM）标记的DNA杂交，形成DNA双链，这会触发切口内切酶Nb.BbvCI对FAM标记的DNA进行选择性切割，产生一个FAM标记的DNA片段。释放出的互补DNA与另一个FAM标记的DNA杂交，导致FAM标记的DNA持续切割，产生大量FAM标记的DNA片段。在微芯片电泳激光诱导荧光检测（LIF）中，对FAM标记的DNA片段进行分离和检测。
CEA的线性范围为130 pg/ml - 8.0 ng/ml，相关系数为0.9916，检测限为68 pg/ml。健康受试者血清样本中CEA浓度在1.3 ng/ml至3.2 ng/ml范围内。癌症患者样本中CEA浓度>15 ng/ml。
该方法可能成为生物医学分析和临床诊断中快速分析CEA及其他肿瘤标志物的有用工具。
