FlowLITE: A protocol to characterize and quantify total antibody isotypes in human plasma using flow cytometry

FlowLITE is a flow cytometry bead-based assay that enables multiplexing and high-throughput quantification of all antibody isotypes from humans, mice, or other species, using small volumes of any fluid specimen. Here, we detail a FlowLITE protocol to quantify and characterize antibody light-chain and isotype expression in human plasma. We describe steps for titrating the capture and reveal antibodies, multiplexing assay beads, and staining samples. We then describe procedures for collecting and analyzing flow cytometry data and quantifying antibodies. For complete details on the use and execution of this protocol, please refer to Babcock et al.¹.