[A new two-stage plan for isolating human alpha1-acidic glycoprotein (orosomucoid). Orosomucoid interacts with ethidium bromide].

Human alpha 1-acid glycoprotein (orosomucoid, AGP) was purified to homogeneity by a two-step procedure using phenol and chloroform deproteinization of serum with subsequent preparative electrophoresis on agarose gel. It was obtained 0.15-0.3 mg of protein from 1 ml of serum. Human alpha 1-AGP binds ethidium bromide but not DNA. Neither other human serum proteins nor mice and rat alpha 1-AGP bind ethidium bromide. This property of human orosomucoid depends on its amino acid sequence rather than on the carbohydrate part of the molecule.