Disclosed are novel protein and peptide compositions comprising soluble and bound forms of immunologically-active blood group antigens including mammalian Rh antigens. In preferred embodiments methods for the isolation and purification of serologically-active human Rh antigens such as D, c, C, E, and e are disclosed. Also disclosed are methods for the adsorption of immunologically-active Rh antigens to solid supports. Diagnostic kits, methods, and devices for the detection of Rh antibodies in clinical and non-clinical samples are also disclosed. Devices, compositions and methods for the isolation, purification and quantitation of anti-Rh antibodies from solution are also provided.