Currently, flow cytometry is a widely used approach for RO assays because it is a fast, flexible and precise platform that can be customized for different molecules and cell types and can be used in a high-throughput platform to screen numerous candidate molecules. 
Flow cytometry has the ability to not only quantify the number of receptors on each cell, but also has the ability to evaluate specific cell subsets that the drug binding to.
Flow cytometry RO assay can also complement other flow cytometry assays such as immunophenotyping analysis or other functional assays that assess mechanisms of action.
Evaluate RO by flow cytometry is highly sensitivity and allows assessment in both preclinical and clinical settings.
The wide variety of sample matrix that can be assessed by flow cytometry, such as fresh whole blood, isolated PBMCs, cells isolated from tissues.