Leishman staining is a basic staining technique used mainly in hematology. It is a Romanowsky-type stain. It’s used to stain peripheral blood smears and bone marrow smears. It is used for the detection of blood parasites and the differentiation of blood cells.
HISTORICAL BACKGROUND
In 1901, a British pathologist, Sir William Boog Leishman, developed the Leishman stain. It is a modification of the Romanowsky stain. This stain was adopted by hematology and parasitology because it is faster and helps in better nuclear and cytoplasmic differentiation.
Leishman also described Leishman–Donovan bodies (amastigote stage of Leishmania donovani).
PRINCIPLE OF LEISHMAN STAIN
Leishman stain is Romanowsky like stain that acts by fixing cells using methanol and meanwhile the dyes bind to nuclei and cytoplasm.
- Methanol acts as fixative
- Methylene blue (basic dye) , stains acidic components (nuclei, RNA) blue–purple.
- Eosin (acidic dye) , stains basic components (hemoglobin, eosinophil granules) pink–red.
PROCEDURE
- Prepare and air dry thin blood smear
- Flood the slide with Leishman stain for 1-2 minutes
- Add buffered water
- Mix gently
- Allow staining for 7-10 minutes
- Wash and air dry
- Examine under oil immersion lens
COMPOSITION
Leishman stain is composed of
- Leishman powder (methylene blue & eosin)
- Acetone-free methanol
- Distilled water (dilution)
RESULT INTERPRETATION
- RBCs appear Pink
- Nuclei of WBCs appear Purple
- Neutrophil granules appear fine lilac
- Eosinophil granules appear Bright red-orange
- Basophil granules appear Deep blue-black
- Platelets appear purple
- Malaria parasite / Leishmania donovani appear Blue cytoplasm with red chromatin dot
USES OF LEISHMAN STAIN
- Differential leukocyte count (DLC)
- Detection of malarial parasites
- Diagnosis of leishmaniasis(LD bodies)
- Study of RBC morphology (anemia)
- Detection of hemoparasites like plasmodium, leishmania, Trypanosoma, Babesia
- Diagnosis of anemia, leukemias, thrombocytopenia
ADVANTAGES
- Simple
- Rapid
- Staining and fixation in one step
- Nuclear and cytoplasmic staining is seen.
DISADVANTAGES
- PH sensitive
- Proper washing is necessary to prevent precipitate formation
PRECAUTION
- Use fresh stain
- Maintain PH of 6.8
- Avoid over staining
- Avoid under washing