A stain for immature granulocytes.

Intended Use :

LYSOCOLOR is intended for use as a rapid stain for immature cells of the neutrophilic granulocytic series, including myeloblasts, if they contain lysomes that are large enough to be resolvable by light microscopy.

Principle :

LYSOCOLOR selectively stains lysosomes (primary granules) in cells of the neutrophilic granulocytic series. Since lysosomes are present in large number in immature granulocytes like promyelocytes and myelocytes, LYSOCOLOR is useful for identification of these young cells.

Reagents :

1. FAA fixative.
2. LYSOCOLOR stain.

Procedure :

1. Fix coverslips containing peripheral blood, buffy coat, or bone marrow in the FAA fixative for 5 minutes.
2. Wash in running distilled water for 1 minute.
3. Stain for 5 minutes with LYSOCOLOR in a staining jar or in a covered Coplin jar. The presence of undissolved dye particles in the stain solution does not affect the performance of the stain.
4. Wash with running distilled water for 30 seconds, blot dry on filter paper, and mount with xylene soluble resin based fixative on cleaned labeled glass slides for light microscopy.

Results :

In myeloblasts and in immature cells of the neutrophilic granulocytic series such as promyelocytes and myelocytes, and lysosomes (primary granules) stain dark purple or black and are sharply defined. In these and other cells, nuclei and remaining cytoplasmic structure stain pale purple to lilac. In leukemic myeloblasts and leukemic promyelocytes, Auer rods, when present, stain dark purple or black. In leukemic lymphoblasts, no granules are seen in the cytoplasm, and the nucleus stains deep purple with well-defined aggregates of nuclear chromatin. In eosinophils and basophils, dark purple or black granular structures of the type found in cells of the neutrophilic granulocytic series are not identified.

This substantially pure reagent is useful for detection of primary granules or lysosomes in normal and abnormal cells of the granulocytic series. The stain is especially valuable for detection of primary granules in immature granulocytes in acute and chronic leukemias, and for the demonstration of Auer rods. Also, identification of primitive granulocytic precursor cells, such as myeloblasts in acute myeloblastic leukemia, is often facilitated with LYSOCOLOR and usually parallels staining reactions obtained with myeloperoxidase and Sudan black B stains. In chronic granulocytic leukemia, granules in promyelocytes and myelocytes stain intensely dark purple or black and are numerous. In leukemic promyelocytes, granules are prominent and often obscure the nucleus. Auer rods stain dark purple or black and can be multiple.