LanthaScreen™ Kinase Activity Assays
Invitrogen's LanthaScreen™ kinase activity assay toolbox has been designed with four key goals in mind:
LanthaScreen™ Activity Assay Mechanism
In a LanthaScreen™ kinase activity assay, kinase, fluorescein-labeled substrate, and ATP are allowed to react. Then EDTA (to stop the reaction) and terbium-labeled antibody (to detect phosphorylated product) are added. In a LanthaScreen™ kinase reaction, the antibody associates with the phosphorylated fluorescein labeled substrate resulting in an increased TR-FRET value. The TR-FRET value is a dimensionless number that is calculated as the ratio of the acceptor (fluorescein) signal to the donor (terbium) signal. The amount of antibody that is bound to the tracer is directly proportional to the amount of phosphorylated substrate present, and in this manner, kinase activity can be detected and measured by an increase in the TR-FRET value.
Schematic of a LanthaScreen™ activity assay using secondary antibodies
In a kinase assay utilizing the terbium labeled anti-Mouse antibody generic reagent, the assay is very similar to the direct format with the exception that the phospho-specific antibody is not labeled and the detection step is performed by the addition of the terbium labeled anti-Mouse antibody. This approach can be applied to target classes beyond kinases.