A new efficient affinity ligand of immunoglobulin yolk (IgY) was made and used in the purification of phospholipase A(2) (Gln49-PLA(2)) homologue from Agkistrodon blomhoffii ussurensis snake venom. Polyclonal antibodies specific against PLA(2) homologue were prepared by immunize hens with PLA(2) homologue as antigen and isolated from egg yolk by an immumoaffinity column coupled with PLA(2) homologue immobilized on Sepharose 4 fast flow. SDS-PAGE and Western-blot analysis confirmed that anti-PLA(2) antibody was electrophoretic ally pure and specific and its activity was increased 40 times. Then, specific immunoglobulin yolk was collected and immobilized on Sepharose 4 fast flow as an immunoglobulin ligand to purify PLA(2) homologue from A. b. ussurensis snake venom and the product displayed just one band on SDS-PAGE. The capacity of IgY immunoaffinity column was determined. The recovery of PLA(2) homologue is over 83% and the productivity is about 13%, the maximum binding capacity of the IgY ligand is 0.3 mg PLA(2) homologue/ml gel. This suggests that the immunoaffinity ligand of IgY is efficient and stable. (c) 2005 Elsevier Ltd. All rights reserved.