Application of peroxidase-antiperoxidase (PAP) staining for detection and localization of dengue-2 viral antigen. II. Observations for the antibody enhancement activity in human monocytes.

Peroxidase-antiperoxidase (PAP) staining was applied to measure the antibody enhancement activity in human monocytes. Increasing in number of infected cells can be seen with increasing of staining intensity of the cells by ordinary light microscope. Shifting of the optimum enhancement activity was found in previously tritiated antiserum indicated that for titration of antibody enhancement activity several dilutions of antiserum should be included in each experiment. Validity of the PAP method was made by the comparison of the results with Infectious Center Assay (ICA). With this technique, titration for antibody enhancement for dengue virus infection can be done with non-expensive equipment and can be kept for comparison for months.