Review of Pigments, IHC and Cytology

Flashcards covering pigments, immunohistochemistry (IHC), and cytology, focusing on key vocabulary and concepts.

Pigment

Substances that can be classified as artifact, exogenous, or hematogenous/endogenous

Exogenous pigments

Pigments that are not created by the body, caused by outside factors

Pigments that the body creates

Endogenous pigments

Argyrophil cells

Cells that can be impregnated with silver but need an external reducer

Argentaffin cells

Cells that can be impregnated with silver and reduce it to a visible metallic form

Prussian blue

Technique for demonstrating iron in tissue

Von Kossa / Alizarin Red S

Technique for demonstrating calcium

Rhodanin (Lindquist) / Rubeanic acid

Technique for demonstrating copper

Fouchet (Hall)

Technique for demonstrating bile

Fontana – Masson; Schmorl

Technique for demonstrating Melanin/Argentaffin

Methenamine silver stain; Polarization

Technique for demonstrating Urates/Gout/Tophus

Grimelius; Churukian-Schenk; Sevier-Munger

Technique for demonstrating Argyrophil

Perls’ Prussian blue stain

Stain used for detection of ferric iron in tissue

Idiopathic hemochromatosis

A condition where too much iron is stored in the body due to a defect in iron absorption

Schmorl technique

Stain used to indicate reducing substances present in tissue such as Melanin, argentaffin granules, and formalin pigment

Fontana-Masson stain

Stain for demonstration of argentaffin substances such as melanin and argentaffin granules of carcinoid tumors

Grimelius argyrophil stain

Stain used for demonstration of argyrophil granules in neurosecretory tumors

Churukian-Schenk method

Method with same purpose, principle, and quality control as Grimelius stain

Gomori methenamine-silver method for urates

Method for demonstration of urate in tissue; used for gout

Bile stain (Hall’s)

Stain used to demonstrate the presence of bilirubin in tissue and distinguish it from other pigments

Von Kossa calcium stain

Stain for identification of the presence of calcium in tissue

Alizarin red S calcium stain

Stain for identification of the presence of calcium in tissue (forms an alizarin red S-calcium complex)

Rhodanine method for copper

Method for detection of copper in tissue, especially in liver, in Wilson disease

ImmunoHistoChemistry (IHC)

A method that uses antibodies to identify, locate, and stain specific protein molecules in tissue section to visualize the target protein under microscope

Antigen

Any foreign (non-self) substance, which is capable of producing an immune response in animals or cell cultures for the production of antibodies

Antibody

A host protein (immunoglobulin) produced by the body’s immune system when it detects antigens

Epitope

Antigenic determinant, is the part of antigen that is recognized by immune system, Abs, B cell

Monoclonal Antibodies

Produced from a single clone of plasma cell, homogeneous population of immunoglobulin reacting with a specific epitope on an antigen. Greater specificity, less sensitivity

Polyclonal Antibodies

Purified from animal serum heterogeneous mixture of antibodies directed against of the same antigen, react with various epitope on an antigen. Less specificity, greater sensitivity

Epitope enhancement or retrieval

Methods used to break down hydrogen bonds formed during formalin fixation in IHC

Positive control

To test a protocol or procedure works with a positive result; included on the same slide as the patient specimen

Negative control

To test the specificity of the antibody; every patient block should have negative control. Treated exactly as other slides except the primary antibody

Internal control

When antigen if interest is present in normal tissue, i.e. s100

Gynecologic (gyn) cytologic specimen

From female genital tract, cervix, endocervix, and vagina. Specimen from these source commonly called “Pap smears”

Nongynecolic (non-gyn) cytologic specimen

From any other body sites, urine, sputum, cerebral spinal fluid, bronchial / gastric / esophageal washings or brushings, pleural / peritoneal / ascites / pericardial fluid, and fine needle aspiration

Pap stain

Cell staining using Papanicolaou stain

Papanicolaou stain (Pap stain)

5 dyes in 3 different solutions: Hematoxylin, Orange G and EA