Histology- Staining

Front 1

What`s Metazoas?

Back 1

Germ cells, blood cells, cells in tissue cultures

Front 2

Two ways of collecting samples:

Back 2

1. Biopsy: from living organisms
2. Necropsy: From dead organism

Front 3

Why do we fixate samples?

Back 3

Because or else enzymes and bacterias will destroy cells by autolysis.

Front 4

Purpose of fixation:

Back 4

Fixation stops metabolic events in the cells either by denaturation of enzymes or by reducing their activity

Front 5

Physical VS. Chemical methods of fixation:

Back 5

Physical:
- Heat (microwave oven)
- Freezing (liquid nitrogen -170 degrees centigrade)
Chemical:
- Immersion into fixative
- Perfusion into the blood vessels of a specimen (formaldehyde)

Front 6

Chemical fixatives:

Back 6

1. Formaldehyde
2. Glutaraldehyde
3. Methanol/ ethanol
4. Acetic acid, tricholracetic acid, picric acid
5. Mercury, osmium, chromium

Front 7

What is embedding?

Back 7

To put tissue sample in special medias where they can be fixed and hardened so that it is possible to cut thin slides for microscope examination

Front 8

Before embedding we must dehydrate the sample by alcohol, a procedure called "clearing". Why?

Back 8

Because the embedding medias are not mixable with water, therefor we must remove water from the tissue.

Front 9

Cutiing:
1. How thin?
2. What are the cutting devices called?

Back 9

1. 4-10 micrometers
2. Microtomes

Front 10

Why do we stain?

Back 10

To make it possible to distinguish tissue and cell components

Front 11

Why do we have to remove (dewax) the embedding medium before staining?

Back 11

Because most dyes are water soluble, therfor the hydrophobic embedding medium must be removed

Front 12

How is a slide made "permanent"?

Back 12

1. Removal of water from the tissue after staining
2. Cover slide by resin

Front 13

Procedure of preparation of a paraffin slide: (12)

Back 13

1. Fixation
2. Washing
3. Dehydration by alcohols
4. Clearing by solvents
5. Embedding in paraffin
6. Cutting
7. Sticking on slide
8. Dewaxing and rehydration
9. Washing
10. Staining, histochemical reactions
11. Dehydration and clearing
12. Resins

Front 14

What is resolving power?

Back 14

The smallest distance between two particles at which we are still able to distinguish them as two separate objects

Front 15

Light microscope:
1. Resolving power
2. Magnification:

Back 15

1. 0,2 microscope
2. 1000- 1500 times

Front 16

General staining:

Back 16

1. Haematoxylin- eosin
2. Masson trichrome
3. Weigert- van Gieson
4. Heidenhain Iron Heamatoxylin

Front 17

Selective staining:

Back 17

1. Weigert resorcin fuchsin
2. Silver methods

Front 18

Haematoxylin- eosin overview:

Back 18

Heamatoxylin stains acidic components: DNA, RNA, ER, nucleus, ribosomes

Eosin stains basic structures of the cell: proteins, cytoplasm, mitochondria, smooth ER, collagen and ECM

Front 19

Results of HE staininig:
1. Nucleus:
2. Collagen:
3. Elastic:
4. Muscle:
5. Notice:

Back 19

1. Blue to black
2. Pink
3. Not stained
4. Pink

Front 20

Results of Weigert van Gieson staining:
1. Nucleus:
2. Collagen:
3. Elastic:
4. Muscle:
5. Notice:

Back 20

1. Brown
2. Red
3. Not stained
4. Yellow
5. Cytoplasm is yellow

Front 21

Azan:
1. Nucleus:
2. Collagen:
3. Elastic:
4. Muscle:
5. Notice:

Back 21

1. Red
2. Blue
3. Not stained
4. Orange- red
5. Erythrocytes are red and mucus blue, and cytoplasm is orange

Front 22

Blue Masson trichrome:
1. Nucleus:
2. Collagen:
3. Elastic:
4. Muscle:
5. Notice:

Back 22

1. Blue to black
2. Blue
3. Not stained
4. Red
5. Erythrocytes are red and mucus blue

Front 23

Yellow Masson trichrome:
1. Nucleus:
2. Collagen:
3. Elastic:
4. Muscle:
5. Notice:

Back 23

1. Blue to black
2. Yellow
3. Not stained
4. Red
5. Red erythrocytes, cytoplasm is stained yellow

Front 24

Green Masson trichrome:
1. Nucleus:
2. Collagen:
3. Elastic:
4. Muscle:
5. Notice:

Back 24

1. Blue to black
2. Green
3. Not stained
4. Red
5. Erythrocytes: red

Front 25

Weigert resorcin fuchsin:
1. Nucleus:
2. Collagen:
3. Elastic:
4. Muscle:
5. Notice:

Back 25

1. Not stained
2. Not stained
3. Violet
4. Not stained

Front 26

Silver staining:
1. Nucleus:
2. Collagen:
3. Elastic:
4. Muscle:
5. Notice:

Back 26

1. Not stained
2. Brown
3. Not stained
4. Grey- black
5. Reticular fibers- black. Used for staining neurons

Front 27

Heidenhain Iron Haematoxylin:
1. Nucleus:
2. Collagen:
3. Elastic:
4. Muscle:
5. Notice:

Back 27

1. Brown to black
2. Not stained
3. Not stained
4. Grey- black
5. Used for staining muscles and in parasitology for detection of worm in tissue.