Latex enhanced immune turbidimetry application prospect

At present, the fluid marker protein detection method mainly adopts the immunological method, by Enzyme Linked immunosorbent assay (Enzyme - Linked ImmunosorbentAssay, ELISA), radiation immunoassay (Radioimmunoassay, RIA) and colloidal gold chromatography (commonly known as "jinbiao") these methods give priority to. Though ELISA method in clinical use for nearly 20 years, but it still exists some fatal weakness, poor quantitative accuracy, long operation time, low degree of automation, generally can only be used for the qualitative detection. RIA high sensitivity, but instability, poor repeatability than ELISA, and there is the danger of radioactive pollution. Although jinbiao method has good stability, but the sensitivity is low, only qualitative, not quantitative. Especially the poor repeatability limit the detection technology in clinical application, especially should not be used for the need to help to diagnose diseases through accurate quantitative humoral marker protein quantitative detection. Therefore, to find a more stable and accurate quantitative detection method of plasma protein has been nearly a decade of research hot spots in the world.

Latex enhanced turbidimetric method (particle - enhanced turbidimetric immunoassay, PETIA) is in recent years the emergence of a more stable and accurate fluid protein homogeneous immune turbidimetric method. PETIA method can be divided into two kinds. One is scattering turbidimetric assay; The other is a transmission turbidimetric assay. The basic principle of the two methods are very similar, is on the surface of polymer latex microspheres in duplicate clone antibody, when crosslinking with antibody microspheres and the antigen, quickly in a short time together and change the reaction liquid of astigmatism or pervious to light performance. Astigmatism or pervious to light performance and reaction liquid (absorbance) change and measured the concentration of the antigen has strong correlation, within a certain range can reflect the concentration of the antigen to be tested. PETIA detection method is in homogeneous reaction system to determine the antigen and antibody response and results. Antigen and antibody response, directly determine the absorbance values, the reaction liquid dispense with ELISA method, incubation and repeatedly washing plate troublesome operation steps, such as a few minutes to get the results, save time and effort. In addition, the nanometer immune turbidimetry procedure simplification also avoids many man-made operation accordingly, environmental factors and reagents such as interference of external factors, stability and repeatability are better, can reflect the material being tested malathion content. Immune turbidimetry sensitivity, although less than ELISA method, but enough to detect many indicators in healthy human plasma protein lower limit, can fully meet the requirements of clinical test.

At present, PETIA detection reagent latex particles are adopted by the inert microspheres, carboxyl microspheres and amination microspheres. Surface modification of rubber latex particles and the combination of antibody is through its amino and carboxyl or antibody on the surface of the covalent binding of amino end, there are a bridge between microsphere and antibody chemical arm, reduces the steric hindrance effect, not only increase the rate of the combination of antibody, but also for antibodies to provide suitable three-dimensional stereoscopic structure, effectively protect the active area of the antibody and antigen. Abroad several companies provide nanoscale surface modification of microspheres particle materials, and widely applied in PETIA. These manufacturers provide particles from 20 nm to 4 microns in diameter, the sensitivity of detection has been greatly improved, and the detection sensitivity can reach 1.0 ng/ml. Can be used as the carrier of polyclonal antibody and monoclonal antibody. The launch of the nano-scale particles solved in monoclonal antibody combining ability is not strong, narrow linear range of clinical detection, interference factors, poor stability of test questions, greatly promote the immune turbidimetric method is widely used in clinic.

Using monoclonal antibody immune turbidimetric crosslinked polymer nanometer microspheres quantitative detection of human serum albumin, induces has the following several aspects of prominent advantages: (1) the operation is simple, but in a few minutes to quickly and accurately detect the contents of serum protein, reflects the progress and evaluate the treatment effect, for the early diagnosis and treatment of disease has important clinical significance. (2) not easily influenced by artificial operation, and the factor of environment detection stability and repeatability are good; (3) to use ordinary biochemical analyzer test, easy to realize automation, popularization and application in grassroots medical institutions at all levels.