This affinity purified antibody has been tested for use in ELISA and by immunofluorescence microscopy. Specific conditions for reactivity should be optimized by the end user. For standard indirect immunofluorescence assays, we recommend paraformaldehyde fixation with detergent permeabilization of cells infected with VSV or transfected with the wild-type VSV-G protein. Staining is quite clean and specific for both sources of the G protein when diluted at least 1/200. At higher concentrations, a filamentous background staining may be present.