Abstract: Isolation of porcine serum IgG by polyphosphate was investigated.The optimal parameters for IgG isolation were determined as follows:the polyphosphate concentration 0.1%(W/V),pH 3.9,and temperature 45 ℃.The recovery rate and purity of extracted IgG are respectively 60.9 % and 64.5 %,and the immunological activity preservation rate is 87.3 % under optimal conditions.The polyphosphate isolation technics is applicable to food industry.

Key words: porcine serum, immunoglobulin G(IgG), polyphosphate, fractionated precipitation