Modified Giemsa stain is a variation of the standard Giemsa stain, where the pH is adjusted from 6.8 to 9.0. This adjustment enhances its differential staining properties, making it useful for identifying and banding human chromosomes. The stain is typically prepared as a 0.4% w/v solution in buffered methanol, with stabilisers to ensure consistency. Giemsa staining works by colouring the nuclei and cytoplasm of white blood cells, with nuclei appearing blue and cytoplasm pink. The use of purified eosin and thiazine dyes minimises lot-to-lot variation, making it ideal for cytogenetic and haematological applications, including chromosomal analysis and blood cell identification.