Pathology - Histological Staining - Special Stains

Front 1

What are the types of Mucin stains

Back 1

1) Neutral - found in glands of the GI tract and in prostate. They stain with PAS
2) Acid (simple, or non-sulfated) - Are the typical mucins of epithelial cells containing sialic acid. They stain with PAS, Alcin blue at pH 2.5, colloidal iron, and metachromatic dyes. They resist hyaluronidase digestion.
3) Acid (simple, mesenchymal) - These contain hyaluronic acid and are found in tissue stroma. Stain with Alcian blue at pH 2.5, colloidal iron, and metachromatic dyes. They digest with hyaluronic acid. Found in sarcomas.
4) Acid (complex, or sulfated, epithelial) - These are found in adenocarcinomas. PAS is usually positive. Alcian blue positive at pH 1, colloidal iron, mucicarmine, and metachromatic stains are positive. They resist digestion with hyaluronidase.
5) Acid (complex, connective tissue) - Found in tissue stroma, cartilage, and bone and include substances such as chondroitin sulfate or keratan sulfate. Stain selectively with Alcian blue at pH 0.5.

Front 2

What are the variety of stains for mucin?

Back 2

1) Colloidal iron ("AMP")
2) Alcian blue
3) PAS - Stains glycogen as well as mucins,
4) Mucicarmine - V. specific for epithelial mucins.

Front 3

What are traditional classification of the staining patterns of biogenic amines

Back 3

1) Chromaffin - have cytoplasmic granules that appear brown when fixed with a dichromate solution - medulla or extraadrenal paraganglion tissues (pheochromocytomas)

2) Argentaffin - reduce a silver solution to metallic silver after formalin fixation - carcinoid tumors of the gut

3) Argyrophil (pre-reduction step necessary)

Front 4

Types of stains for argentaffin include:

Back 4

1. Diazo (diazonium salts)
2. Fontana-Masson
3. Schmorl's
4. Autofluorescence

Front 5

Types of stains for chromaffin include:

Back 5

1. Modified Giemsa
2. Schmorl's
3. Wiesel's

Front 6

Types of stains for argyrophil include:

Back 6

1. Grimelius (Bouin's fixative preferred)
2. Pascual's

Front 7

Where is melanin found

Back 7

Found in the skin, eye, and substantia nigra. It may also be found in melanomas.

Front 8

What are the types of melanin stains

Back 8

Fontana-Masson

Schmorl's method

DOPA-oxidase

Formaldehyde-induced fluorescence

Front 9

What is the Fontana-Masson

Back 9

Relies upon the melanin granules to reduce ammoniacal silver nitrate (but argentaffin, chromaffin, and some lipochrome pigments also will stain black as well).

Front 10

How does Schmorl's method work

Back 10

Uses the reducing properties of melanin to stain granules blue-green.

Front 11

What is the most specific method of melanin staining

Back 11

DOPA-oxidase

Front 12

How does DOPA-oxidase work

Back 12

Requires frozen sections for best results, but paraffin sections of well-fixed tissues may be used.
The stain works because the DOPA substrate is acted upon by DOPA-oxidase in the melanin-producing cells to produce a brownish black deposit.

Front 13

What technique removes melanin

Back 13

Bleaching techniques - make use of a strong oxidizing agent such as potassium permanganate or hydrogen peroxide.

Front 14

What does pseudomelanin stain with

Back 14

PAS
True melanin isn't PAS positive

Front 15

What are Lipochrome (lipofuschin) pigments?

Back 15

breakdown products within cells from oxidation of lipids and lipoproteins

Front 16

Where are lipochrome/lipofuschin pigments commonly found

Back 16

most commonly in heart, liver, CNS, and adrenal cortex (zona reticularis).

Front 17

What are ceroid pigments and where are they found?

Back 17

Less highly oxidized lipochrome pigments found in the testis interstitium and seminal vesicle

Front 18

Where is hemosiderin found

Back 18

in areas of old hemorrhage or be deposited in tissues with iron overload

Front 19

What method is used to stain iron tissues

Back 19

Perl's iron stain

Front 20

How is Perl's iron stain produced?

Back 20

The section is treated with dilute hydrochloric acid to release ferric ions from binding proteins.
Then these ions then react with potassium ferrocyanide to produce an insoluble blue compound (the Prussian blue reaction)

Front 21

What methods are used for calcium staining

Back 21

Hematoxylin - blue color

VonKossa stain - silver reduction

Alizarin red S - orange-red lake

Azan - differentiates osteoid from mineralized bone

Front 22

When is a VonKossa stain used?

Back 22

Demonstrates phosphates and carbonates, but these are usually present along with calcium.

Most useful when large amounts are present, as in bone.

Front 23

When is Alizarin red S used?

Back 23

at pH = 4.2
It works best with small amounts of calcium (such as in Michaelis-Gutman bodies).

Front 24

Where are urates present in the body

Back 24

in tissues at sodium urates

Front 25

How are urates fixed

Back 25

With 95% or absolute alcohol because they are soluble in aq. solns

Front 26

What stains are for urates

Back 26

Methenamine silver - stains urates black.

Front 27

What is a special property of urates

Back 27

birefringent on polarization

Using a red plate, the crystals show negative birefringence (yellow color) when the crystal's long axis is aligned in the direction of the slow wave. At 90 degrees to this, the crystals will be blue.

Front 28

What stains are used for copper

Back 28

rubeanic acid and rhodanine stains are utilized to detect the cytoplasmic accumulation of copper in the liver.

Front 29

What is Wilson's disease

Back 29

autosomal recessive disease resulting from decreased serum ceruloplasmin, the blood protein that transports serum copper

Front 30

What are examples of exogenous pigments and minerals

Back 30

carbon, asbestos, silica, street drugs, tatto pigments,

Front 31

How does carbon appear and how is it imaged?

Back 31

- appears as anthracotic pigment in the lungs
- can be distinguished from melanin by doing a melanin bleach
-

Front 32

What characterizes asbestos in tissue?

Back 32

these crystals are highly irritative and highly fibrogenic. The fibers become coated with a protein-iron-calcium matrix, giving them a shish-kebab appearance.

Front 33

What is used to stain asbestos?

Back 33

an iron stain

Front 34

How is silica visualized?

Back 34

It is inert and can't be stained

It's demonstrated by white birefringence on polarization

Front 35

What characterized tattoo pigment

Back 35

black, inert, non-polarizable.

Red tattoo pigment often contains cinnabar (which has mercury in it).

Front 36

How are minerals visualized?

Back 36

In general, minerals are best demonstrated by microincineration techniques or by scanning electron microscopy with energy dispersive analysis (SEM-EDA).

Front 37

How is fat stained?

Back 37

oil red O (ORO) stain can identify neutral lipids and fatty acids in smears and tissues

Front 38

Why are fresh smears or cryostat sections of tissue necessary in fat stains

Back 38

because fixatives containing alcohols, or routine tissue processing with clearing, will remove lipids

Front 39

What stains are used to visualize CT?

Back 39

1) trichrome stain
2) reticulin stain
3) elastic tissue stain

Front 40

What is an elastic tissue stain used for?

Back 40

helps to outline arteries, because the elastic lamina of muscular arteries, and the media of the aorta, contain elastic fibers.

Front 41

What stains ID inflammatory cells in peripheral blood and tissue

Back 41

1) Wright-Giemas and Giemsa stains
2) leukocyte alkaline phosphatase (LAP)
3) tartrate-resistant acid phosphatase (TRAP)
4) myeloperoxidase (MPO).

Front 42

What is a special property of giemsa stains

Back 42

One property of methylene blue and toluidine blue dyes is metachromasia. This means that a tissue component stains a different color than the dye itself. For example, mast cell graules, cartilage, mucin, and amyloid will stain purple and not blue, which is helpful in identifying these components.

Front 43

What is a LAP stain used for

Back 43

- in determining whether a high peripheral blood leukocytosis is a reactive process or a leukemia (chronic myelogenous leukemia, or CML).
- more differentiated cells in the reactive process will stain more readily with LAP, while leukemic cells will not

Front 44

What does a high LAP score indicate

Back 44

high score generally indicates a "leukemoid reaction" or reactive condition (with an infection or other inflammatory process)

Front 45

What does a low LAP score indicate

Back 45

a low score suggests CML (leukemia)

Front 46

What is the use of a TRAP stain

Back 46

help diagnose a rare leukemia known as hairy cell leukemia.

Front 47

What is an MPO stain used for

Back 47

to identify cytoplasmic granules characteristic of myeloid cells - helps differentiate between myeloid and lymphoid cells

Front 48

What is used to stain bacteria

Back 48

H&E

Front 49

How does bacteria appear upon staining

Back 49

Bacteria appear on H and E as blue rods or cocci regardless of gram reaction. Colonies appear as fuzzy blue clusters.

Front 50

What is used to stain gram(-) bac.

Back 50

Brown and Brenn (or the Brown and Hopps modification)

Front 51

What stain fungi

Back 51

H&E: blue
PAS: red
Methenamine silver: most sensitive

Front 52

What demonstrates donovan bodies and leishmania?

Back 52

Giemsa stain

Front 53

What is a Warthin-Starry stain used for

Back 53

to ID Spirochetes - but they are difficult to ID

Front 54

What is an AFB (acid fast bacilli) stain used to

Back 54

uses carbol-fuchsin to stain the lipid walls of acid fast organisms such as M. tuberculosis, myobacteria, cryptosporidium, isospora, and the hooklets of cysticerci.

Front 55

What are the methods of AFB stains

Back 55

1) Ziehl-Neelsen method
2) Kinyoun's method
3) Fite stain
4) auramine stain - most sensitive, req. fluorescence microscope

Front 56

What is a Gomori methenamine silver (GMS) stain used for

Back 56

fungi and for Pneumocystis carinii (jirovecii) - organisms are outlined by the brown to black stain

Front 57

What stains fungi and Pneumocystis carinii (jirovecii)

Back 57

GMS

Front 58

What does a PAS stain visualize?

Back 58

glycogen, mucin, mucoprotein, glycoprotein, as well as fungi

Front 59

What is a PAS stain useful for

Back 59

outlining tissue structures--basement membranes, capsules, blood vessels, etc.

Front 60

What stains can have a high background

Back 60

GMS, PAS