Advantages of fluorescent microspheres compared with colloidal gold as a label in immunochromatographic lateral flow assays.

Label selection is of vital importance for immunochromatographic assays. In this study, the fluorescent microsphere test strip and colloidal gold immunochromatographic test strip (FM-ICTS and CG-ICTS) were developed for the detection of Escherichia coli O157:H7 on the basis of the sandwich format. Two types of labels, namely, colloidal gold particles (CG) and carboxyl-modified fluorescent microspheres (FMs), were compared while coupling with anti-E.