May Grünwald Giemsa staining Two stains are combined in this process: May-Grünwald and Giemsa. When mixed in a buffered aqueous solution both stains selectively act in the following way: the May-Grünwald stains the acidophilic cells and the neutrophilic granulations of leucocytes; Giemsa stains the monocyte and lymphocyte cytoplasm and the nuclear chromatin.