Slide Preparation and Microscopy

Question 1

Fixation

Answer 1

preservation of the specimen in tissue preparation. This is done with formalin, which is 37% formaldehyde

Question 2

Embedding

Answer 2

sectioning in tissue preparation to allow for thin slides.

Question 3

Mounting

Answer 3

attatching specimen to slide for better viewing. This is done using heat or an adhesive

Question 4

Staining

Answer 4

distinguishes between tissues for slides

Question 5

Steps of slide preparation

Answer 5

1. Fixation
2. Embedding
3. Mounting
4. Staining

Question 6

Properties of formalin

Answer 6

37% formaldehyde. Formalin allows proteins to still react

Question 7

Steps for Embedding

Answer 7

1. Dehydration
2. Clearing of alcohol
3. Paraffin application

Question 8

What is important to know happens during embedding?

Answer 8

Lipids are lost. They will show as blank spaces in the slide to show where they were

Question 9

Commonly used dyes for staining

Answer 9

H&E and PAS

Question 10

What is H & E staining?

Answer 10

Staining done using Hematoxylin (an acid) or Eosin (a base)

Question 11

What is PAS?

Answer 11

Periodic acid-Schiff reaction

Question 12

What elements are stained by acids?

Answer 12

Proteins and extracellular fibers like collagen

Question 13

Eosin

Answer 13

an acidic dye that shows up as red in slides

Question 14

Acidic dyes attract _____

Answer 14

basic structures with a positive charge

Question 15

What is hematoxylin

Answer 15

a classic basic dye that shows up blue/purple in slides

Question 16

Basic dyes attract _____

Answer 16

acid structures with a negative charge

Question 17

What elements are stained by bases?

Answer 17

Heterochromatin, DNA, RNA, endoplasmic reticulum

Question 18

What is the Feulgen reaction?

Answer 18

stains DNA. It distinguishes between DNA which reacts and RNA which does not react

Question 19

The PAS stains what structures what color?

Answer 19

basement membrane and glycogen, which become pink

Question 20

What color are elements stained with a basic dye?

Answer 20

blue/purple

Question 21

What color are elements stained with an acidic dye?

Answer 21

Red/pink

Question 22

What cellular structures does Alcian blue stain?

Answer 22

Mucin which becomes light blue

Question 23

What cellular structures does Azan stain?

Answer 23

Nuclei, red blood cells, and muscle; bright red.

Also stains mucin and basement membrane; light blue

Question 24

What cellular structures does Congo red stain?

Answer 24

Amyloid which becomes red

Question 25

What cellular structures does Giemsa stain?

Answer 25

red blood cells which become pale pink, and nuclei with become blue

Question 26

What stain is used to differentiate between human and bacterial cells?

Answer 26

Wright stain

Question 27

What stain is used to differentiate between muscle and connective tissue?

Answer 27

Masson's Trichrome

Question 28

3 colors of Masson's Trichrome + what each color stains

Answer 28

Blue; nuclei Blue/green; connective tissue Red; keratin, muscle, and hyaline

Question 29

What does orange G stain?

Answer 29

Red blood cells which are stained orange

Question 30

What does Sudan black & osmium stain?

Answer 30

Myelin which is stained brown/black

Question 31

What stains mucus/mucopolysaccharides in the cornea?

Answer 31

Alcian blue

Question 32

What stains amyloid in the cornea?

Answer 32

Congo red

Question 33

What can be diagnosed with alcian blue staning in the cornea?

Answer 33

Macular dystrophy

Question 34

What can be diagnosed with congo red staining in the cornea?

Answer 34

Lattice dystrophy

Question 35

What stains hyaline in the cornea?

Answer 35

Masson's trichrome (it becomes dark red)

Question 36

What can be diagnosed with Masson's trichrome staining in the cornea?

Answer 36

Granular dystrophy

Question 37

What type of dystrophy is a combination of lattice and granular dystrophy?

Answer 37

Avellino dystrophy

Question 38

What two dystrophies are Avellino dystrophy a combination of?

Answer 38

Lattice and Granular dystrophy

Question 39

What stains carbohydrates in the cornea?

Answer 39

PAS (periodic acid-Schiff) (becomes pink)

Question 40

What can be diagnosed with PAS staining in the cornea?

Answer 40

Fuch's endothelial dystrophy

Question 41

Enzyme digestion

Answer 41

Results in structures disappearing after digestion

Question 42

Enzyme histochemistry

Answer 42

reagent causes a colored precipitation product

Question 43

Innumocytochemistry

Answer 43

antibodies bind to components of the cell. This can be detected by fluorescein tagging

Question 44

Direct antibody binding

Answer 44

the antibody that has been tagged to fluorescein will attach directly on to the antigen

Question 45

Indirect antibody binding

Answer 45

the antibody is not tagged but will bind to the antigen. Then a tagged antibody will bind to the untagged antibody (could result in multiple antibodies tagged to each other)

Question 46

How is hybridization detected?

Answer 46

Via a radioactive label or fluorescein

Question 47

What is autoradiography?

Answer 47

Labelling of precursors with a radioactive label

Question 48

micrometer

Answer 48

μm (10^-6)

Question 49

nanometer

Answer 49

nm (10^-9)

Question 50

millimeter

Answer 50

mm (10^-3)

Question 51

picometer

Answer 51

pm (10^-12)

Question 52

How does atomic force microscopy work?

Answer 52

Uses a physical problem on live cells to scan the specimen

Question 53

Methods of Embedding

Answer 53

Use frozen sections or paraffin embedded specimens

Question 54

Tools for embedding

Answer 54

The tissue is sectioning using a microtone or a steel knife