Study On The Immunochromatographic Techniques

Early pregnancy detection is crucial for the health of fetus and pregnant woman. Early pregnancy test depends on the measurement of human chorionic gonadotrophin( HCG ). HCG is the principal signal from an early pregnancy and detected only during pregnancy.HCG can be detected by bioassay, immunoassay and immunochromatography assay. Immunoassay includes agglutination inhibition assay and immunolabel. With time, animals and expertise involved, bioassay is quite labor intensive, expensive and insensitive. Bioassay is not used in clinic now. With insensitive, non-specific and non-quantity, agglutination inhibition assay is replaced by other methods. Immunolabel is much more sensitive and specific and can be used for quantitaive measurement in hospital laboratories. However, with complex operation process, highly trained operator, expensive sophisticated equipment, it is not suitable for the middle and small scale hospital and home usage.Based on the rapid immunochromatographic techniques and the principle of sandwich-type assay, this paper develops a test system of HCG in human's urine. The test system consists of glass fiber as sample pad material and conjugate pad material, Nitrocellulose membrane as membrane material, absorbent paper as absorbent pad material and PVC as adhesive card material.This paper aims to optimize test system by changing the sample pad's dipping time, the test line's position, antibody's concentration on the test line and the marker material and observing the influences of these parameters on the test system.The test system developed by this paper is in the format of strip. The test system can rapidly and qualitatively detect HCG in pregnant women's urine and achieves the aims of early pregnancy detection. The test is a simple, easy to operate and suitable for hopital, communication and home test.