Chemiluminescent photographic detection of Salmonella anatis and an antibody against human cytomegalovirus using horseradish peroxidase as the label

Abstract

Salmonella anatis and the antibody (Ab) against human cytomegalovirus (HCMV) in serum were detected by chemiluminescent photographic detection (CPD) on nitrocellulose (NC) membranes using horseradish peroxidase (HRP) as the label and X-ray film. HRP was first estimated on NC membranes with a limit of detection of 0.5–2.5 amol. When used to detect the Ab against HCMV, the antigen was mobilized on the NC membrane before the incubation of human serum, then the HRP labelled sheep Ab against human IgM was incubated again. Finally, the washed membrane was put into direct contact with a piece of filter-paper that had previously absorbed the CL substrate mixture and was exposed to the X-ray film. Fifty-seven human serum samples were thus detected for the Ab against HCMV. The results were in good agreement with the routine enzyme-linked immunosorbent assay method, but the CPD procedures used an HRP-labelled sheep Ab solution 1000 times more dilute. Salmonella anatis was detected with a limit of detection of 100 bacteria.