Giemsa stain is a mixture of methylene blue, eosin, and azure B. It is specific for the phosphate groups of DNA and attaches itself to adenine-thymidine rich regions. It is a high contrast polychromatic stain. It is used as a standard stain for differential staining of blood and bone marrow smears. It stains different cells in different colour. Giemsa is commonly used stain for G-banding of chromosomes. In G-banding studies, heterochromatic region of chromosomes is stained dark(G-bands) with giemsa whereas euchromatic regions are stained light(R-bands). This helps in identification of chromosomal aberrations.