Standardized Flow Cytometry Assay Using Dried Recombinant Antibody Panels for CAR T Cell Characterization.

Flow cytometry is commonly used to assess critical quality attributes of Chimeric Antigen Receptor T (CAR T) cells, including viability, phenotype, and transduction efficiency. Conventional liquid reagent workflows require multiple preparation steps, which can introduce variability and differences in operator-dependent handling. Preformulated dried recombinant antibody panels provide an alternative format that combines recombinant antibody technology with a ready-to-use configuration. Recombinant antibodies offer defined specificity and reduced lot-to-lot variability, while the dried format reduces preparation steps and simplifies reagent handling. Here, we present a step-by-step workflow for CAR T cell analysis using dried recombinant antibody panels. The protocol includes sample staining, data acquisition, and analysis, and is accompanied by a schematic overview of the workflow. Representative staining results are shown to illustrate panel application, and differences in hands-on time compared to a conventional liquid reagent workflow are highlighted. The examples provided demonstrate how these panels can be used to streamline the multiparametric characterization of CAR T cells. Overall, this work provides a practical framework for implementing dried recombinant antibody panels in flow cytometry-based CAR T cell analysis.