Histology Staining Agents Overview

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Questions and Answers

Which mounting medium has the highest refractive index among the listed options?

Brun's fluid

Apathy's medium (correct)

Glycerin jelly

Gum Arabic (Farrant’s)

What is the purpose of sealing the margins of the coverslip?

Increase the refractive index

Enhance the visibility of the section

Prevent escape/evaporation of fluid (correct)

Prevent contamination of the slide

Which staining agent is known to act as a ripening agent and contains mercury?

Heidenhain’s

Eosin Y

Harris’ (correct)

Weigert’s

Which antibody is commonly used in immunohistochemistry?

IgG Signup and view all the answers

What is the primary color of the nuclei after the acid alcohol differentiation step in the H & E staining process?

Blue Signup and view all the answers

What is the purpose of 0.5% acid alcohol in staining procedures?

To remove stains from skin Signup and view all the answers

Which mordant is used in Weigert's hematoxylin staining?

FeCl3 Signup and view all the answers

In the context of epithelial tumor markers, what does a positive CK 7 and negative CK 20 indicate?

Lung and breast tumors Signup and view all the answers

Which method is used to remove a coverslip from a section?

Incubation in xylene Signup and view all the answers

What is the purpose of Eosin Y in histological staining?

Counterstain Signup and view all the answers

What does the abbreviation 'LUBO' in epithelial tumor markers refer to?

Lung, Uterus, Breast, Ovary Signup and view all the answers

Which staining method utilizes ammonia water as a blueing agent?

H & E staining Signup and view all the answers

What is the primary use of Acridine orange in histological staining?

Staining RNA and DNA Signup and view all the answers

Which of the following fluids is specifically mentioned for use in frozen section preparations?

Brun's fluid Signup and view all the answers

Which type of slides do slotted staining dishes hold?

5-19 slides Signup and view all the answers

What distinguishes Sudan III from Sudan IV in lysochrome staining?

Sudan III is orange, while Sudan IV is red Signup and view all the answers

Study Notes

Stains and Reagents

Ehrlich’s and Harris’ utilize iodate and HgO2 respectively as ripening agents.
Iron hematoxylin uses iron as a mordant and is significant in staining processes.

Staining Techniques

Weigert’s stain employs FeCl3 as a mordant, crucial for examining connective tissues and Entamoeba histolytica.
Heidenhain’s stain incorporates ferric ammonium sulfate for mordanting.
Mallory’s PTAH uses sunlight/K+ for staining fibrin.
Copper hematoxylin specifically targets spermatogenesis.

Eosin Types

Eosin Y (yellowish) is the most commonly used cytoplasmic/acidic stain.
Eosin B (bluish) appears deep red, while ethyl eosin, Eosin S, and Eosin alcohol soluble variants offer flexibility in staining.

Staining Equipment

Coplin jar holds 5-9 slides; slotted staining dishes accommodate 5-19 slides.
Metal/glass staining racks can hold 10-30 slides for various staining procedures.

H & E Staining Steps

Process begins with xylol for deparaffinization followed by a descending alcohol gradient for rehydration.
Nucleus typically stains light blue, transitioning to blue with ammonia water, while red staining indicates cytoplasm.

Pap Smear Staining

Hematoxylin serves as a nuclear stain; OG-6 and EA (Eosin Azure) are utilized for cytoplasmic staining of mature superficial and immature cells respectively.

Other Stains

Benzidine indicates hemoglobin presence, acridine orange differentiates RNA and DNA via fluorescence.
Congo red stains elastic tissue, amyloid, and myelin; malachite green detects Ascaris eggs.

Adhesives Used in Histology

Mayer’s egg albumin, dried albumin, gelatin, and Poly-L-lysine are common adhesives, with 3-APES being noted for cytology.

Mounting Media

Resinous media has a higher refractive index (e.g., DPX = 1.532), while aqueous media is typically used for lipid preservation.
Glycerin jelly is the standard mounting medium for fat stains.

Slide Restaining and Maintenance

Stain removal occurs with 0.5% acid alcohol and restaining techniques involve xylene and potassium permanganate.
Broken slides can be salvaged by transferring sections to clean slides using a mixture of butyl acetate and durofix.

Ringing in Histology

Sealing coverslip margins prevents fluid evaporation and immobilizes the coverslip while avoiding slide sticking.

Immunohistochemistry Insights

Enzyme histochemistry primarily utilizes trypsin and protease; IgG is the most widely used antibody.
Monoclonal antibodies are derived from mice, while polyclonal types originate from various animals, including rabbits and goats.

Epithelial Tumor Markers

CK 7 is positive, and CK 20 is negative in tumors from lung, uterus, breast, and ovary (“LUBO” pattern).
CK 20 positive and CK 7 negative characterize stomach and colon tumors; transitional cell carcinoma shows a dual positivity.
EMA is positive in carcinomas, while CEA differentiates between adenocarcinoma and mesothelioma.

Additional Markers

TTF-1 is a critical transcription factor for thyroid activity, relevant in examining associated carcinomas.

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Description

This quiz delves into various staining agents and mordants used in histology, including Ehrlich's, Gill's, and Delafield's. Learn the functions and applications of iron hematoxylin, eosin, and tungsten hematoxylin in staining techniques. Enhance your understanding of these essential reagents in histological preparations.