Assay Method Information

Assay Name:  HCV NS5B RdRp enzyme assay
Description:  An on-bead solid phase homogeneous assay was used in a 384-well format to assess NS5B inhibitors (WangY-K, Rigat K, Roberts S, and Gao M (2006) Anal Biochem, 359: 106-111). The biotinylated oligo dT12 primer was captured on streptavidin-coupled imaging beads (GE, RPNQ0261) by mixing primer and beads in 1× buffer and incubating at room temperature for three hours. Unbound primer was removed after centrifugation. The primer-bound beads were resuspended in 3× reaction mix (20 mM Hepes buffer, pH 7.5, dT primer coupled beads, poly A template, 3H-UTP, and RNAse inhibitor (Promega N2515)). Compounds were serially diluted 1:3 in DMSO and aliquoted into assay plates. Equal volumes (5 μL) of water, 3× reaction mix, and enzyme in 3× assay buffer (60 mM Hepes buffer, pH 7.5, 7.5 mM MgCl2, 7.5 mM KCl, 3 mM DTT, 0.03 mg/mL BSA, 6% glycerol) were added to the diluted compound on the assay plate. Final concentration of components in 384-well assay: 0.36 nM template, 15 nM primer, 0.29 μM 3H-UTP (0.3 μCi), 1.6 U/μL RNAse inhibitor, 7 nM NS5B enzyme, 0.01 mg/mL BSA, 1 mM DTT, and 0.33 μg/μL beads, 20 mM Hepes buffer, pH 7.5, 2.5 mM MgCl2, 2.5 mM KCl, and 0.1% DMSO.Reactions were allowed to proceed for 24 hours at 30° C. and terminated by the addition of 50 mM EDTA (5 μL). After incubating for at least 15 minutes, plates were read on an Amersham LEADseeker multimodality imaging system.IC50 values for compounds were determined using ten different [I]. IC50 values were calculated from the inhibition using the four-parameter logistic formula y=A+((B−A)/(1+((C/x)^D))), where A and B denote minimal and maximal % inhibition, respectively, C is the IC50, D is hill slope and x represents compound concentration.
Affinity data for this assay
 

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