Week 1

Question 1

Fixation

Answer 1

• organs are placed in solutions of stabilizing or cross linking compounds
• tissues normally cut thin to allow fixative to fully diffuse

Question 2

formalin

Answer 2

• widely used fixative

- reacts with amine groups to prevent degradation

Question 3

dehydration

Answer 3

water is extracted from tissue sample through multiple ethanol solution of increasing ethanol, last solution is 100% ethanol

Question 4

clearing

Answer 4

ethanol replaced with alcohol and embedding medium which gives tissue translucent appearance

Question 5

infiltration

Answer 5

• tissue is infiltrated with paraffin

- place tissue in melted paraffin and stick in oven to evaporate clearing solution and make tissue stick to paraffin

Question 6

trimming

Answer 6

-hardened block trimmed with microtome; slice put onto slide.

Question 7

dye

Answer 7

use dye to color tissue and make parts of cell easier to see

Question 8

basophilic dyes

Answer 8

-bind to anions

Question 9

acidophilic dyes

Answer 9

-bind to cations

Question 10

Hematoxylin and eosin

Answer 10

H:
- stains DNA, RNA-rich proteins and matrix of cytoplasm
-dark blue/purple color
E:
-stains cytoplasmic structures and collagen
-pink counter stain

Question 11

why do fat cells cytoplasm show up clear when using H&E

Answer 11

clearing: cytoplasm of adipocyte filled with fat and is washed in clearing; since there is no fat in cytoplasm there is nothing for stain to adhere to

Question 12

floater tissue

Answer 12

tissue from another sample that contaminates your sample and causes incomplete reading.