The JAK1 (JH2 Pseudokinase Domain) Inhibitor Screening Assay Kit is a fluorescence polarization-based assay designed for screening and profiling small molecules that displace the fluorescently labeled probe (JH2 probe 1) from the JH2 pseudokinase domain of JAK1. This kit comes in a convenient 384-well format, with enough recombinant human JAK1 (JH2 Pseudokinase Domain), buffer, and fluorescently labeled JH2 probe 1 for 384 reactions.

This assay requires a fluorescent microplate reader capable of measuring fluorescence polarization (FP) to read the FP signal. For more information on the principles of FP, visit fp_assays.pdf ().

Figure 1: Illustration of the assay principle. The assay is based on the competition between the test compound and the JH2 probe for the purified JAK1 (JH2 Pseudokinase Domain). JH2 probe 1 is incubated with JAK1 (JH2 Pseudokinase Domain) in the presence or absence of inhibitor. When the JH2 probe 1 is bound to the JH2 pseudokinase domain it has high FP due to its restricted movement. A competitive inhibitor prevents the probe from binding to the JH2 pseudokinase domain, therefore most of the probe is in free form and has low FP. Compared to a control without inhibitor, FP decreases proportionally to the inhibitor concentration.