Abstract: By the fermentation reactor and Pichia pastoris expression system， the expression of recombinant porcine interfer\|α （rPoIFN\|α） was induced with methanol. The rPoIFN\|α was purified by ammonium sulfate precipitation， Q\|Sepharose fast flow chromatography and gel filtration in turn. 6\|week\|old BALB/c mice were immunized for three times with purified rPoIFN\|α， then mouse myeloma cells and the spleen cells of the BALB/c mice were fused. Five hybridoma clones secreting antibody against rPoIFN\|α were obtained by screening with the indirect ELISA and 3-5 times of subcloning. The five McAbs belonged to IgG I isotype， and showed specificity reaction to rPoIFN\|α by Western\|blot. ELISA showed that their antigen binding sites were the same. This paper is beneficial to study the applications of monoclonal antibody（McAb） against rPoIFN\|α in immunology and disease diagnosis.

Key words: recombinant porcine interfer\, α, monoclonal antibody, specificity identification