Specificity#: This product can be used as a negative control for direct FITC immunofluorescence staining (e.g.. Flow Cytometry) when using mouse monoclonal antibodies to human cell surface antigens of isotype IgM. This enables an estimation of non-specific binding of mouse monoclonal antibodies to cell surface components in peripheral blood and tissue. Suitable for whole blood, Ficoll-separated preparations, frozen and paraffin embedded sections. This antibody recognises a rat cell surface marker and therefore cannot be used as a negative control in the species.