Titration curves of RCV-A1 and RHDV sera from rabbits in the blocking ELISA. RCV-17, 18, 21: sera from domestic rabbits infected with RCV-A1. These sera were first diluted with negative serum to produce inhibition levels of 25 – 35%. RHDV-W7 - W23: sera from wild rabbits naturally infected with RHDV showed low levels of cross reactivity. All sera were tested at dilutions of 1:10, 1:40 and 1:160 in PBS-TY.