Flow cytometric analysis in transfected cell lines. Mock-transfected BaF3, BaF3/PAR-2, or BaF3/PAR-2^{Arg36 → Ala36} (mutant) cells were incubated with 20 μg/mL anti–PAR-2 antibody for flow cytometric analysis using a FITC-conjugated secondary antibody, as outlined in the Materials and Methods. As shown, comparable cell-surface receptor expression is seen in both cell lines expressing PAR-2 (<95% immunoreactive cells), whereas no immunoreactivity is detectable using mock-transfected BaF3 controls.