Li Pan1, Jingjin Zhao2, Yong Huang2, Shulin Zhao3, Yi-Ming Liu4. 1. 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. 2. 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. 3. 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. Electronic address: zhaoshulin001@163.com. 4. Department of Chemistry and Biochemistry, Jackson State University, 1400 Lynch St., Jackson, MS 39217, USA. Electronic address: yiming.liu@jsums.edu.
Abstract
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: This method may become a useful tool for rapid analysis of CEA and other tumor markers in biomedical analysis and clinical diagnosis.
BACKGROUND: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. METHODS: 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. RESULTS: 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 cancerpatients was found to be >15 ng/ml. CONCLUSIONS: This method may become a useful tool for rapid analysis of CEA and other tumor markers in biomedical analysis and clinical diagnosis.
Authors: Bo Huang; Hongkai Wu; Devaki Bhaya; Arthur Grossman; Sebastien Granier; Brian K Kobilka; Richard N Zare Journal: Science Date: 2007-01-05 Impact factor: 47.728