LAB 1 Embedding

Question 1

Purpose of Embedding

Answer 1

• Removes water and replaces it with paraffin wax
• Occurs after tissues have been processed
• Facilitates microtomy + long-term storage of tissue blocks

Question 2

Processing provides __ support to tissues, whereas embedding provides __ support

Answer 2

Processing provides internal support to tissues, whereas embedding provides external support

Question 3

List equipment used in embedding tissues

Answer 3

• Molten wax dispenser
• Hot surface
• Cold surface
• Metal molds
• (Warm) Forceps

Question 4

Once the tissue is suspended in wax and placed on a cold surface…

Answer 4

WORK QUICKLY to press all edges of tissue to bottom EVENLY

Question 5

Most tissues are embedded at a…

Answer 5

Slight angle, “cut side down”

Question 6

What 2 indicators suggest follow-up action ?

Answer 6

1. Tissue with soft consistency/ feels greasy (excluding fatty tissue)
2. Tissue smells like xylene/ alcohol

Question 7

Why might a block need to be re-embedded ?

Answer 7

• Tissue is crammed into a casette
• Mold used is too small
• Tissue not evenly pressed against mold and casette
• Air bubble within paraffin

Question 8

What happens if mold is too small for the tissue ?

Answer 8

• Choose a different mold
• Difficulty in microtomy

Question 9

Once the mold is initially filled halfway with paraffin, place the mold on a __ surface

Answer 9

Once the mold is initially filled halfway with paraffin, place the mold on a cold surface

Question 10

When embedding, rotate between __ forceps

Answer 10

When embedding, rotate between warm forceps

Question 11

What happens after the mold has been placed on the cold plate ?

Answer 11

As soon as the wax starts to turn white, WORK QUICKLY to press all edges of tissue EVENLY to the bottom

Question 12

What do you do after pressing the tissue firmly on the cold surface ?

Answer 12

WITHOUT PUTTING THE MOLD BACK DOWN, fill it to the top with paraffin

Question 13

BEFORE ALL OF THE WAX SOLIDIFIES, what needs to be done ?

Answer 13

The original tissue cassette must be pressed EVENLY on top of the mold

Question 14

Multiple specimens in one block should…

Answer 14

Multiple specimens in one block should NOT TOUCH EACH OTHER

Question 15

How is a block re-embedded ?

Answer 15

• The block is placed on a warming tray to soften and remove the paraffin
• Tissue is re-embedded