The LANCE® Ultra KinaSelect™ Ser/Thr kit is intended for selecting the optimal peptide substrate for serine and threonine (Ser/Thr) kinases. Kinase activity is measured in aLANCE® time-resolved fluorescence resonance energy transfer(TR-FRET) assay using five different ULight™-labeled peptide substrates with their corresponding europium (Eu)-labeled anti-phospho-antibodies. Substrate/antibody pairs giving the best performance can then be used for further assay development and optimization. The five ULight™-labeled peptides andEu-labeled antibodies selected for the KinaSelect kit were found to generate signal with over 80% of a panel of 184 Ser/Thr kinases.

LANCE Ultra TR-FRET technology provides a two-component kinase assay that combines direct labeling of the kinase substrate with ULight™, an innovative emission dye for optimum binding efficiency, reducing steps and assay prep time. Validated for over 310 kinases, we provide data transparency by supplying:

• Test conditions: Rapid assay setup to move straight into optimized assay performance
• S:B data: Confidence in proven performance of the kinase on specific substrates; no guessing
• Phospho-motifs: Substrate sequences are provided
• Assay options: Multiple substrates are tested so you can select the best peptide sequence and S:B for your kinase

In LANCE Ultra kinase assays, the binding of a Eu-labeled anti-phosphosubstrate antibody to the phosphorylated ULight-labeled substrate brings donor and acceptor molecules into close proximity. After irradiation of the kinase reaction at 320 or 340 nm, the energy from the Eu donor is transferred to the ULight acceptor dye, which in turn generates light at 665 nm. The intensity of the light emission is proportional to the level of ULight-substrate phosphorylation.