A method for double immunoperoxidase staining of the blood-brain barrier cell elements was developed using 2mB6 monoclonal antibodies specifically visualizing brain capillary antigen and antibodies to glial fibrillary acidic protein (GFAP). The method is based on consecutive visualization of antigen structures in one section: first using a substrate mixture containing diaminobenzidine (brown coloring) and then a mixture with diaminobenzidine and CoCl(2) (blue coloring). This method visualizes cerebral capillary cells and fibrillar astrocytes interacting with them. The method can be used in all variants of double immunoperoxidase studies and for immunodetection of several antigens in immunoblotting analysis.