Also written as eosin-5'-maleimide.
Fluorescent dye used in conjunction with flow cytometric analysis for the assessment of red cell disorders, specifically hereditary spherocytosis, hereditary pyropoikilocytosis/hereditary elliptocytosis.
The dye binds primarily to band 3 protein, part of a complex of transmembrane proteins (ankyrin) that maintain the red cell structure by connecting to the network of structural filaments just below the membrane. It also binds to a degree with the Rh protein, Rh glycoprotein and CD47.
In red cell membrane disorders, there are defects in one of several genes, either in the ankyrin complex or in the cytoskeletal filaments (spectrins). Abnormalities in these complexes reduces the amount of binding.