The Research Of Gold Immunochromatomatographic Strip For Adulterate Raw Milk

Based on the disadvantages of current detection methods for adulterate raw milk,gold immunochromatographic strip applying to test adulterate raw milk was researched and prepared. Firstly, polyclonal antibodies ofαs-casein andκ-casein which were characteristic caseins in adulterate raw milk were successfully prepared. Secondly,monodisperse and high-quality gold solution was prepared by microwave heating, and conjugated with the polyclonal antibody ofκ-casein after identification.In the end,the conjugation solidified to polyester membrane, the standard ofκ-casein and goat anti-rabbit IgG were immobilised on nitrocellose membrane to prepare for kit.Enzyme-linked immunosorbent assay (ELISA) was used in order to test the titer and specificity Of polyclonal antibodies ofαs-casein andκ-casein.The purification method of antiserum was ammonium sulphate precipitation.The purified polyclonal antibodies ofαs-casein andκ-casein may be conjugated with gold solution.Effections of different heating methods , heating time and reducer addition during preparation of the colloidal gold were compared. The result showed that the method of microwave was more siutable for preparation of small diameter gold particle in short time.The various factors and conditions of the immunochromatographic lateral-flow assay were explored, and the optimal reaction conditions of the assay were ascertained. GICAs for rapid detection ofκ-casein was successfully established.The method of diluting the samples was boldly attempted according to the condition of high content in tested material.Various propertiesof the gold immunochromatographic strip forκ-casein were evaluated. The detection methods of ELISA and electrochemical immuno-sensor were compared with GICAs.The method producing GICA forκ-casein could also be used as reference in the development of the test for adulterate raw milk.