Preparation

Question 1

Parafin Sections

-fixation -deca_____ -processing (dehydration, clearing, impr______) -______ -sectioning

Answer 1

-fixation -decalcification -processing (dehydration, clearing, impregnation) -embedding -sectioning

Question 2

Fixation -prevents? -maintains?

Answer 2

-breakdown, autolysis of cells -penetrate tissues quickly -kill cells quickly and evenly -maintain tissue morphology

Question 3

Types of fixatives

Answer 3

-formaldehyde -alcohol

Question 4

Formaldehyde and fixation -natural state -dissolves in ___? -dilution factor to form formalin? -forms what kind of links?

Answer 4

-formaldehyde exists as a gas • dissolves in water, available as formalin (40%) • dilute 1:10 for use (10% formalin) • forms cross links with proteins

Question 5

Decalcification -removes _____?

Answer 5

-complete removal of calcium • reasonable speed • absence of tissue damage • non-impairment of subsequent staining

Question 6

Processing - Dehydration

Answer 6

• several changes of alcohol - ethanol, IMS, methanol, acetone - drives out water

Question 7

Processing - Clearing

Answer 7

• replace alcohol with a chemical miscible with impregnation medium - benzene, toluene, xylene

Question 8

Processing - Impregnation

Answer 8

-changes of molten wax -50-60 degrees

Question 9

Embedding

Answer 9

done in a machine in wax cooled

Question 10

Sectioning

Answer 10

-4-6um -drying

Question 11

Freezing

• r____
• more tissue _________ retained
• makes tissue _____ for sectioning
• rapid freezing gives ______ results

Answer 11

• rapid
• more tissue components retained
• makes tissue rigid for sectioning
• rapid freezing gives better results