Reproducibility with PathHunter iONCscan Services
The PathHunter PD-1 Checkpoint Assay was performed with Pembrolizumab (anti-PD-1 antibody) and PD-L1 ligand presenting cell line. Data show consistent EC50’s and S/B on three different runs of the assay within the same plate with less than 4% relative standard deviation (%RSD). For more details on how the assay works, please visit the ‘Assay Principle’ tab above.
Better Sensitivity, Quicker Results than Reporter Gene Assays
Assay |
PathHunter Assay |
Competitor Assay |
IC50 ng/mL |
54 |
927 |
Assay Time |
< 5 hours |
22 hours |
Signal:Background Ratio |
11.1 |
7.8 |
Using the same anti-PD-1 antibody (BioLegend Cat. No. 329912), we were able to compare the assay performance of our PathHunter PD-1 signaling assay to a commercially available reporter gene assay, and observed that the PathHunter PD-1 assay demonstrated more than 15-fold better sensitivity than the reporter gene assay, with a better assay window, and returned results in
one-quarter the total assay time.
Screen and Identify Both Small Molecule and Biologic Drugs

PD-1 is known to be phosphorylated by an as yet unidentified Src family kinase, which results in recruitment of the SHP-1 protein to the phosphorylated tail of the PD-1 receptor. Testing of the PathHunter PD-1 assay with small molecule inhibitors that are known to inhibit several known Src family kinases has shown inhibition of the SHP-1 recruitment to PD-1, demonstrating that the PathHunter PD-1 assay can be used to identify novel small molecule inhibitors of this exciting immunotherapy target.