GoldMag Particles-based Chemiluminescence Enzyme Immunoassay For Determination Of Total Testosterone In Human Serum

Testosterone (T) is one of the important sex hormones and its level in the blood directly affect one’s health. The determination of testosterone concentration can help the clinical diagnosis of the related diseases. However, there are many structural analogues and endogenous substances in the blood, which have similar antigen active site with testosterone. On the other hand, the testosterone is not easily separated from the binding protein. Therefore, it is difficult to accurately determinate the testosterone in human serum.The GoldMag particles, which have our own intellectual property rights, have superparamagnetism and higher capacity for coupling specific protein. These features could make assay system reaching high detection sensitivity, wide linear range respectively. In addition, it has stable when magnetic separation during the detection method performance. Therefore, GoldMag particles has been widely applied in various fields, not only for immunoassay based on sandwich principle, but also in sensitively detecting the small substances in human serum based on competitive immunoassay.The GoldMag particles coated with T antigen were used as a solid phase for the immunoassay, and the horseradish peroxidase (HRP)-luminol-H2O2chemiluminescent system was chosen as the detection system. The magnetic enzyme chemiluminescence immunoassay(MECLIA) for the detection of total testosterone in human serum, which is simple, high specificity, sensitivity and reproducibility was established.Several parameters which affect assay system including conditions for preparation of immunomagnetic beads, the amount of antigen and antibody added, the condition of competitive immunoassay were studied and optimized. The proposed method had a larger linear range of0.05-5ng/ml, and the linear correlation coefficients R2for the standard curve was0.99.This chemiluminescence immunoassay based GoldMag particles can be applied to detect testosterone with good precision at concentrations as low as0.038ng/ml. The method has been successfully used in the determination of testosterone for120human sera of clinical samples, and the results showed that there is a good correlation with the commercialized chemiluminescence immunoassay kit with a correlative coefficient of0.97587. This method has exhibited great potential in the diagnostic kit development and will be used in the clinical analysis of total testosterone in human serum.