The PathHunter PD-1 (SHP1) Signaling Bioassay Kit provides an easy-to-use cell based assay to measure drug potency and detect neutralizing antibodies. This bioassay asseses ligand (e.g. Anti-CD47 Antibody (Ab-2; Clone B6H12.2)) based on activation of PD-1, SHP1 Checkpoint activity via detection of SH2 Recruitment. The included cell line overexpresses ProLink-tagged PD-1 target protein and EA-tagged SH2 domain protein. Upon activation of the receptor by its ligand or an agonist antibody, recruitment of SH2 domain protein to the phosphorylated receptor tail leads to production of EFC signal. Bioassay kits are a convenient, ready-to-use format which contains all materials needed to run the assay, including single-use vials of cryopreserved cells, cell plating media, control agonist, detection reagent, and assay plates.