2.15. In Vitro Kinase Assay

A kinase profiler service from Millipore was used. An Rb-ME stock solution was prepared to 50 × final assay concentration in 100% DMSO to assess the direct inhibitory effect of Rb-ME against Src and Syk. The reaction was initiated by incubating with Mg/ATP mixture. After 40 min. at room temperature, the reaction was stopped by adding 0.5% phosphoric acid. Then, 10 μL of the reaction solution was spotted onto a P30 filtermat and washed 4 times for 4 min. in 0.425% phosphoric acid and once in methanol before drying and measuring by scintillation counting.