Immunocytochemical detection of antibodies to Epstein-Barr virus nuclear antigen by a streptavidin-biotin-complex assay.

An immunocytochemical staining for the detection of antibody to Epstein-Barr virus nuclear antigen in cell smears was developed by using a three-dimensional complex of streptavidin and biotin labeled with horseradish peroxidase as the detector system. The presence of antibody against Epstein-Barr virus nuclear antigen was revealed by a dark staining of the nuclei of Raji cells. A significant correlation was found between the titers obtained with our assay and titers obtained by anticomplement immunofluorescence on 110 serum samples. Our assay did not require an Epstein-Barr virus-negative serum source for fresh complement and gave a permanent record of the reaction that could easily be observed under an ordinary light microscope.