(A) Immunocross-reactivity of SPLA2 and DrPLA2 with anti- SPLA2 serum using a simple sandwich ELISA. Each experiment was performed by direct coating of one phospholipase (100 ng/well) with a fixed dilution of 1:500 for the serum tested. (B) Immunoblot analysis, SPLA2 solution (200 μg) (lane 1), pure SPLA2 (15 μg) (lane 2) and DrPLA2 (50 μg) (lane 3) using anti-SPLA2 serum at 1:1000 dilution. (C) Effect of anti- SPLA2 antibody on PLA2 activity. SPLA2 (12 U) was incubated with various concentrations of anti-SPLA2 in 0.1 M Tris-HC1, 0.1 M NaCl (pH 8.5) for 2 h at 20°C. Similarly, DrPLA2, (12 U) was incubated with anti-SPLA2. After incubation, the remaining activity of PLA2s was measured using PC emulsion in the presence of 4 mM NaTDC and 8 mM CaCl2.