Quantitative transformation of hemoglobin into stable tetramers

A method is described for the preparation of human or bovine hemoglobin with a covalent bridge, formed by bispyridoxal-tetraphosphate, between the beta chains. The yield is 95% of the total hemoglobin. The location of the two molecules of bispyridoxal-tetraphosphate in the tetramer has been established. The functional properties of the cross-linked hemoglobin, its stability, and particularly, the simplicity of the method for its preparation, make it a promising candidate for an acellular blood substitute.