Assay Method Information

Assay Name:  TR-FRET (Time Resolved FRET) Assay
Description:  This BTK competition assay measures compound potency (IC50) for the inactivated state of Bruton's Tyrosine Kinase using FRET (F rster/Flouresence Resonance Energy Transfer) technology. The BTK-Eu complex was incubated on ice one hour prior to use at a starting concentration of 50 nM BTK-Bioease™: 10 nM Eu-streptavidin (Perkin-Elmer Catalog# AD0062). The assay buffer consisted of 20 mM HEPES (pH 7.15), 0.1 mM DTT, 10 mM MgCl2, 0.5 mg/ml BSA with 3% Kinase Stabilizer (Fremont Biosolutions, Catalog # STB-K02). After 1 h, the reaction mixture from above was diluted 10 fold in assay buffer to make 5 nM BTK: 1 nM Eu-Streptavidin complex (donor fluorophore). 18 μl of a mixture of 0.11 nM BTK-Eu and 0.11 nM Kinase Tracer 178 (Invitrogen, Catalog # PV5593) with BTK-Eu alone as no negative control, was then dispensed into 384-well flat bottom plates (Greiner, 784076). Compounds to be tested in assay were prepared as 10× concentrations and serial dilution in half-log increments was performed in DMSO so as to generate 10 point curves. To initiate the FRET reaction, compounds prepared as 10× stock in DMSO was added to the plates and the plates were incubated 18-24 h at 14° C.After the incubation the plates were read on a BMG Pherastar Fluorescent plate reader (or equivalent) and used to measure the emission energy from the europium donor fluorophore (620 nm emission) and the FRET (665 nm emission). The negative control well values were averaged to obtain the mean minimum.
Affinity data for this assay
 

If you find an error in this entry please send us an E-mail