Purification of porcine β-actin and comparison of serum reactivities with α-actin and β-actin. A: Coomassie-stained polyacrylamide gel showing purification of recombinant porcine β-actin. Nickel affinity chromatogryphy (1) and electro-elution (2) are shown. Protein mass standards in kDa are indicated in column S; B: Comparison of reactivity with α-actin and β-actin. Group 1, i.e. immunised animals, showed significantly stronger reaction with cytoskeletal actin (P ≤ 0.0002). No difference between α- and β-actin reactivities was observed in group 2 sera (P ≤ 0.2034).