New method to produce equine antirabies immunoglobulin F(ab′)2 fragments from crude plasma in high quality and yield

A new method consisting of protein G affinity chromatography, pepsin digestion, followed by a combination of protein A affinity chromatography and ultrafiltration, was proposed to produce equine antirabies immunoglobulin F(ab′)2 fragments in higher yield and bioactivity than the current WHO method.