Kleihauer stain

a combination of aniline blue and Biebrich scarlet red used for detection of fetal-maternal hemorrhage (FMH) as fetal cells in the maternal blood and taking advantage of the differential resistance of fetal hemoglobin to acid treatment of a standard blood smear prior to staining Syn Kleihauer-Betke stain, Kleihauer-Betke test, KB stain, KB test