Related Experiment Video
Updated: Apr 7, 2026
Fluorescent Dye Labeling of Erythrocytes and Leukocytes for Studying the Flow Dynamics in Mouse Retinal Circulation
Published on: July 3, 2017
Stability of eosin-5'-maleimide dye used in flow cytometric analysis for red cell membrane disorders
Simmi Mehra1, Neetu Tyagi1, Pranav Dorwal1
1Department of Pathology, Medanta, The Medicity, Gurgaon, India.
Background:
The eosin-5'-maleimide (EMA) binding test using flow cytometry is a common method to measure reduced mean channel fluorescence (MCF) of EMA-labeled red blood cells (RBCs) from patients with red cell membrane disorders. The basic principle of the EMA-RBC binding test involves the covalent binding of EMA to lysine-430 on the first extracellular loop of band 3 protein.
Methods:
In the present study, the MCF of EMA was analyzed for samples derived from 12 healthy volunteers (controls) to determine the stability (i.e., the percentage decrease in fluorescence) of EMA over a period of 1 year.
Results:
Comparison of periodical MCF readings over time, that is, at 2-month intervals, showed that there were no significant changes in mean channel fluorescence for up to 6 months; however, there was a significant decrease in MCF at 8 months.
Conclusion:
For optimal dye utilization, EMA remained stable only for up to 6 months. Therefore, we recommend reconstitution of the dye every 6 months when implementing this test and storage at -80℃ in dark conditions.
