Enhanced CD123 detection on OCI-AML5 cells by flow cytometry

The UB Flow Core Kit is designed to deliver strong fluorescence signals with minimal background for detecting low-abundance antigens by flow cytometry. We tested it on OCI-AML5 cells with low CD123 surface expression - approximately 5,000 molecules per cell, measured using an antigen quantification kit. Cells were stained with a biotinylated anti-CD123 antibody and analyzed using AF488 fluorescence detection.

Compared with conventional fluorescent streptavidin (SA), the Core Kit increased background-subtracted fluorescence (ΔMFI) approximately 15-fold. Adding the UB Flow Booster Kit increased this to approximately 100-fold, while kit background remained close to unstained cells. This combination of strong signal and low background yielded staining indices of 78 with Core and 440 with Core + Booster, substantially exceeding the staining index of 5 achieved with conventional fluorescent streptavidin.