Detection of Recombinant Lysostaphin Using Antibody Sandwich Enzyme-linked Immunoadsorbent Assay (ELISA)

The double-antibody-sandwich enzyme-linked immunoadsorbent assay (ELISA) for detection of rLysostaphin in humans was developed and established in this study. rLysostaphin of high purity (>95 %) produced in Shanghai Hi-Tech United Bio-Technological Research & Development Co., Ltd., China (SHUBRD) was used to produce a rabbit anti-rLysostaphin polyclonal antibody. The standard curve of rLysostaphin polyclonal antibody that was constructed showed that the lowest range of detection was found at 0.98 ng of rLysostaphin/mL, and the curve exhibited linearity preferably from 0.98 to 500 ng of rLysostaphin/mL. When three serum samples of the same batch were assayed for 6 replicates, and more 3 samples from different batches for 6 replicates, the average intra-assay and inter-assay coefficient variances (CV) were 6.4 % and 6.5 %, respectively. The relative recovery rate was 98.6 % when quantitative standard antigens were added to the serum. The present method for detection of rLysostaphin in serum is specific, highly sensitive and highly precise, and exhibited a low CV and will be helpful in the further study of rLysostaphin pharmacokinetics and promising in clinical applications.