Dynamic response of hCG with anti-hCG under different pH environment using atomic force microscopy

• Main Authors: Yu-Fang Huang, 黃于芳
• Other Authors: Adam Shih-Yuan Lee
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/68700827199548990049

碩士 === 淡江大學 === 生命科學研究所碩士班 === 96 === Human chorionic gonadotropin (hCG) is a well-known index of the pregnancy test. There are some studies also indicated that the hCG exhibits many functions such as the diagnosis of ectopic pregnancy miscarriages, tumor markers of some cancers, Down’s syndrome screens and clinical medications. Atomic force microscopy (AFM) possess the high spatial resolution and immense force sensitivity, it is regarded as a powerful instrument to investigate the nanostructures of samples in air, liquid or vacuum environment. In this study, dynamic responses of hCG with anti-hCG under different pH environments were studied by AFM, and the unbinding forces were also be discussed. The hCG and anti-hCG were immobilized on the glass surface and the AFM tips, respectively. The unbinding forces have measured by AFM under different buffer solutions (pH 2.2, pH 4.2, pH 6.2, pH 7.2, pH 8.2 and pH 10.2). Within the acidic range, the mean value of the unbinding force between the hCG and anti-hCG complex showed a rapidly increase from pH 2.2 to 6.2. A maximum value of 503.8 ± 77.6 (pN) was measured at neutral environment, followed by a sharp decreasing with rising pH values (pH 6.2 ~ 10.2).