Stains & CD markers
Special stains
Enzyme cytochemistry
Copyright: 2003-2024, PathologyOutlines.com, Inc.
PubMed Search: Enzyme cytochemistry
Special stains
Enzyme cytochemistry
Author: Nat Pernick, M.D.
Last author update: 1 July 2013
Last staff update: 3 August 2023
Copyright: 2003-2024, PathologyOutlines.com, Inc.
PubMed Search: Enzyme cytochemistry
Table of Contents
Definition / general | Methods | Uses by pathologists | Microscopic (histologic) imagesCite this page: Pernick N. Enzyme cytochemistry. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/stainsenzymecytochemistry.html. Accessed December 24th, 2024.
Definition / general
- Detects enzymatic activity in cytoplasm
- Advantage over immunocytochemistry is determination of enzyme's intracellular localization and intensity of catalytic activity (for research purposes)
- Flow cytometry and immunocytochemistry are often preferred to determine presence of enzyme molecule (but not catalytic activity or localization)
- Enzyme product unites with coupler, which produces localized color at site of enzyme activity
- Fresh smears are preferred, especially for myeloperoxidase; if not possible, store unstained slides away from light
Methods
- Simultaneous capture: reagent in incubation medium combines with reaction product (example: diazo method for alkaline phosphatase)
- Post-incubation coupling: insoluble reaction product is coupled with a colored or opaque substance (example: Rutenburg and Seligman method for acid phosphatase)
- Self-colored substrate reaction: water-soluble dye is made insoluble when enzyme removes a hydrophilic group, leading to colored precipitate at site of enzyme activity
- Intramolecular rearrangement: produces a colored insoluble precipitate at sites of enzyme activity of an otherwise colorless substrate (University of Iowa)
Uses by pathologists
- Used for these enzymes: acid phosphatase, alkaline phosphatase, myeloperoxidase, Sudan black B, nonspecific esterase
- Also: acetyl cholinesterase, adenosine triphosphate, adenylate cyclate, catalase, cytochrome oxidase, 5' nucleotidase, nucleoside diphosphatase, succinic dehydrogenase and thiamine pyrophosphatase
Microscopic (histologic) images
AFIP images
AML-M2 (left), AML-M1 (right) show myeloperoxidase staining
AML-M1: Sudan black B positive granules
AML-M0: myeloblasts are negative for MPO
AML-M4: chloroacetate and nonspecific esterase
Images from other servers:
AML-M4: non-specific esterase
AML-M4: lysozyme
