Cytochemical Staining Techniques

Flashcards for Cytochemical Staining Techniques in Clinical Hematology

Cytochemistry

The microscopic study of biochemical components of cells.

Cytochemical stains

Special stains used for staining peripheral blood and bone marrow smears that help characterize immature cells and classify and differentiate different types of leukemias.

Perls’ Prussian Blue

Stains non-heme iron (Fe3+).

Periodic Acid–Schiff (PAS)

Stains glycogen and glycoproteins.

Sudan Black B (SBB)

Stains lipids.

Enzymatic Staining Methods

Detection of Enzymatic Activity.

Perls’ Prussian Blue Reaction

A histochemical reaction detecting ferric iron (Fe3+) in tissues, blood smears, or bone marrow smears. It is used in the diagnosis of hemosiderosis and hereditary hemochromatosis.

Periodic Acid–Schiff (PAS) Reaction

Stains cytoplasmic glycogen, glycoproteins, mucoproteins, and high-molecular-weight carbohydrates present in various hematopoietic cells.

Sudan Black B (SBB)

A fat-soluble dye that stains lipids present in the cytoplasm of granulocytes and monocytes; differentiates AML from ALL; SBB results correlate closely with patterns observed in myeloperoxidase (MPO) and chloroacetate esterase (CAE) methods; increased stability of SBB-stained smears when exposed to sunlight or heat and stored for prolonged periods.

Myeloperoxidase (MPO)

Found in neutrophils, eosinophils, and monocytes but not in lymphocytes; in the primary (or azurophilic) granules of cells in the myeloid lineage.

Cyanide-Resistant Peroxidase

Positive only in eosinophils; differentiates eosinophils from monocytes and granulocytes

Nonspecific Esterase

Used to identify monocytes and their precursors and macrophages. It is diffusely positive in monocytes and macrophages but negative in granulocytic cells.

α-Naphthyl butyrate

A marker for monocytes, promonocytes, and monoblasts; most specific for monocyte differentiation.

α-Naphthyl acetate

A marker for monocytes, megakaryocytes, plasma cells, and platelets; more sensitive for monocyte differentiation.

Specific esterase staining with naphthol-AS-D chloroacetate esterase (CAE)

Used to identify immature granulocytic cells in acute leukemias; a marker for early cells of the myeloid lineage. If found in blasts, this marker is considered evidence of myeloid origin

Leukocyte Alkaline Phosphatase (LAP)

Located in the tertiary or microvesicular granules of segmented neutrophils, bands, and some metamyelocytes. Distinguishes between chronic myelogenous leukemia (decreased or negative LAP score) and leukemoid reactions and myeloproliferative disorders.

Acid phosphatase

A lysosomal enzyme in many tissues and hematopoietic cells. Activity has been shown to be higher in T lymphocytes than in B lymphocytes.

Terminal deoxynucleotidyl Transferase (TdT)

A specific marker for primitive lymphoid populations; observed in pre-B and pre-T lymphoblasts but is absent in lymphocytes.