The Study Of DNA Electrochemical Biosensor For Detection Of Breast Protein Marker Genes

Breast cancer is a common serious to female health, the incidence rate increased rapidly every year, and the invasion and metastasis of breast cancer is the leading cause to death among breast cancer patients. Diagnosis of invasion and metastasis of breast specific marker protein markers by the diagnosis clinical breast cancer for early detection and treatment which provide the scientific base to research, is of great academic innovation and clinical application. DNA electrochemical biosensor is the current genetic testing technology, which is rapid, sensitive, accurate, simple adn economical, having a wide range of applications in the fields of molecular biology and biological engineering.In this paper, electrochemical alternating current (AC) impedance technology is used to detect breast protein (MG) marker genes in the DNA electrochemical sensor. And then detected by electrochemical impedance technique before and after DNA hybridization, and optimized the experimental conditions, constructed electrochemical DNA biosensor based on the new method of detecting breast gene. Experimental results show that sodium dodecyl sulfate (SDS) as a non-specific adsorption removal agent, which can effectively remove the single or double-stranded DNA on the electrode surface. The best time of SDS elution was 3 min, the best time for a fixed probe was 30min, optimal hybridization temperature and time were 37℃and 20min. With the optimal experimental conditions, using electrochemical impedance measured the breast protein marker gene, which in the 1.0×10 ^-9～2.0×10 ^-8mol/L concentration range, detection response signal was a good linear relationship (r = 0.9992), the detection limit was 5.0×10 ^-9 (S / N = 3) , to achieve an accurate determination of breast sensitive marker gene protein.In addition, this article also carry out a preliminary study of the practical samples of breast protein (MG) marker genes, to test the clinical samples, and compare with PCR amplified products the gel method study which was traditional detection of breast protein marker genes. The positive samples from clinical practice to extract the mRNA, and then transcribed into cDNA, as to transcribed cDNA as a template for RT-PCR amplification, which was amplified products. Builting this new methods with the optimal experimental conditions, the amplified products were detected after diluting 100 times, and carried out the study of recovery experiments and negative samples, comparing with the traditional gel electrophoresis. The results show that the new detection was sensitive,high accuracy, so the actual samples provide direct experimental evidence for scientific in further clinical testing, and laid the foundation of clinical application for the final invasion and metastasis of breast cancer diagnosis in early research...