Recognition of native congopain in an ELISA by anti-C2 antibodies produced at week 3, 6, 9 and 11 by rabbits immunised with C2 alone, or in combination with different adjuvants. Native congopain was coated onto ELISA plates (1 μg/mL in 50 mM carbonate buffer, pH 6, 16 h, 4 °C) and probed for recognition by IgG (100 μg/mL) collected at weeks 3, 6, 9 and 11 from rabbit A1 (○; solid line), A2 (○; broken line), B1 (▲; solid line), B2 (▲; broken line), F1 (×; solid line), F2 (×; broken line), R1 (■; solid line), and R2 (■; broken line), and non-immune rabbit IgG (♦). Absorbance readings at 405 nm represent the average of two experiments. Goat anti-rabbit IgG-HRPO labelled antibodies were used for detection and ABTS/H₂O₂ as substrate as described in Materials and methods. Rabbit B1 was not bled at week 3.