ABSTRACT
Objective To develop a visible detection system prepared by protein microarrays which was based on GoldMag particles-labeled technique and compare the results of detection using the protein which was labeled with GoldMag particles and colloidal gold.Methods Human IgG was printed on the glass slides modified with epoxy groups,and goat anti-human IgG conjugated with GoldMag particles and colloidal gold respectlively was then added on the slide.The glass slides were incubated,and then the black images of microarray spots were produced by immuno-gold-silver staining method and observed by naked eyes and recorded with common flatbed scanner.Results The high signal-to-noise ratio could be obtained when the optimized procedures of GoldMag particles-labeling probe were introduced to the protein chip.The conditions of optimum assay were as follows:the spotting concentration of human IgG was 0.2 mg/ml,the glass slides were incubated at 37 ℃ for 2 hour to immobilize human IgG,and the silver enhancement time was 10 min-15 min.Parallelly,the optimized conditions for colloidal gold were as follows:the spotting concentration of human IgG was 0.1 mg/ml,the slides were incubated at 37 ℃ for 1 hour to immobilize human IgG,and the silver enhancement time was 15 min-20 min.Conclusions GoldMag particles-labeled protein technique is comparable to colloidal gold in applying to protein microarrays.The method is considerably simple and practical,and the protein labeled by GoldMag particles could be quantitative.