Degranulation of rat basophil lines induced by AllerT and its respective individual COPs T1, T2 and T3. Beta-hexosaminidase release was measured from RBL-2H3 cells loaded with sera obtained from r Bet v 1-sensitized mice and stimulated in panel A. with 5.7 nM rBet v 1, T1, T2, T3, AllerT or left unstimulated, n=10; in panel B: with 57 nM rBet v 1, T1, T2, T3, AllerT or left unstimulated, n=3; panel C: Beta-hexosaminidase release from RBL-2H3 cells loaded with 2 sera (dilutions 1:10, 1:50 and 1:100) obtained from r Bet v 1-sensitized mice and stimulated with serial concentrations of Bet v 1. Degranulation was measured using a colorimetric assay and is expressed in OD. Median and quartiles are indicated as horizontal bars. Data were analyzed by a non-parametric paired t test and compared to rBetv1. **p <0.01.