Patent ID: 8512706

Claim:
A composition comprising F(ab′) 2 antibody fragments substantially free from albumin and whole antibodies and substantially free of pyrogens, wherein the composition binds to a purified antigenic molecule or a mixture of antigenic molecules found in spider venom, and wherein the F(ab′) 2 antibody fragments are obtained by a method which comprises: (a) contacting a source of antibodies with pepsin under conditions to prepare an antibody digest containing F(ab′) 2 antibody fragments, wherein the antibody digest is substantially free of unhydrolyzed antibodies; and (b) treating the antibody digest with two steps of ammonium sulfate precipitation, (i) one step at about 16% to about 22% weight by volume of ammonium sulfate, and (ii) another step at about 32% to about 38% weight by volume of ammonium sulfate, to thereby obtain a suspension containing F(ab′) 2 antibody fragments substantially free of whole antibodies.