It is specific for the phosphate groups of DNA and attaches itself to regions of DNA where there is a high amount of adenine – thymine binding. Giemsa staining is used in Giemsa banding, commonly called G-banding , to staining chromosomes and is often used to generate a karyogram (chromosome map). It can identify chromosomal aberrations such as translocations and rearrangements . [ citation needed ]
This trophozoite stains Trichomonas vaginalis , which presents with a green discharge and motile cells on the wet prep. [ citation needed ]
Giemsa stain is also a differential stain , such as when it is combined with Wright stain to form Wright-Giemsa stain. It can be used to study the adherence of pathogenic bacteria to human cells . It stains human and bacterial cells separately in purple and pink, respectively. It can be used for the histopathological diagnosis of Plasmodium species that cause malaria  and some other spirochete and protozoan blood parasites. It is also used in Wolbachia cell stain in Drosophila melanogaster . ,citation needed ]
The Giemsa stain is a classic blood film stain for peripheral blood smears and bone marrow specimens . Erythrocytes are pink in color, platelets are pale pink, lymphocyte cytoplasm shows spots sky blue, monocyte cytoplasm shows light blue and leukocyte nuclear chromatin stains magenta. It is also used to visualize the classic “safety pin” shape in Yersinia pestis .
Giemsa stain is also used to visualize chromosomes. This is particularly relevant for the detection of cytomegalovirus infection, where the classical finding would be “owl-eye” viral inclusions. 
Giemsa stains the fungus Histoplasma , Chlamydia bacteria, and can be used for the identification of mast cells.
Giemsa’s solution is a mixture of methylene blue, eosin and azure B. The stain is usually prepared from commercially available Giemsa powder.
A thin film of the sample is fixed on a microscope slide by immersing it in pure methanol for 30 seconds or by pouring a few drops of methanol onto the slide. The slide is immersed in freshly prepared 5% Giemsa stain solution for 20–30 min (10% solution can be used in 5–10 min in emergency), then washed with tap water and dried. is left for.