Performance evaluation of QuantiBRITE phycoerythrin beads

Area of Science:

• Immunology
• Flow Cytometry
• Biotechnology

Background:

• Standardization of antibody quantitation is crucial for reliable flow cytometry analysis.
• Phycoerythrin (PE) beads offer a potential solution for standardizing measurements of antibodies bound per cell (ABC).

Purpose of the Study:

• To evaluate the performance of QuantiBRITE PE beads for standardizing CD4 and CD69 quantitation.
• To assess the precision, inter-instrument variability, and temporal stability of PE bead-based standardization.

Main Methods:

• Whole blood was stained for CD4 quantitation using a no-wash/no-lyse format.
• Whole blood was activated and stained for CD69 quantitation using a lyse-no-wash format.
• QuantiBRITE PE beads were used to standardize antibody bound per cell (ABC) measurements.

Main Results:

• CD4 ABC quantitation showed high precision (<1.0% CV within-assay, <5.0% CV across instruments).
• CD4 ABC quantitation demonstrated good temporal stability (1.3%-3.2% CV within-donor over 2 months).
• CD69 ABC quantitation showed acceptable precision (<3.0% CV within-assay) but higher temporal variability (2%-24% CV within-donor over 1 month).

Conclusions:

• QuantiBRITE PE beads are a valuable tool for standardized flow cytometry analysis across laboratories.
• The beads provide a simple and robust method for quantitating antibody expression levels in terms of ABC when used with 1:1 PE conjugates.