STEP 5: EMBEDDING

Question 1

or casting or blocking is the process by which impregnated tissue is placed into a precisely arranged position in a mold containing a medium which is then allowed to solidify

Answer 1

Embedding

Question 2

Embedding is done at __________ the melting point of the wax then ___________

Answer 2

5-10°C above the melting point of the wax

cooled rapidly in a refrigerator at -5°C or immersed in cold water

Question 3

Process by which a tissue is arranged in precise positions in the mold during embedding, on the microtome before cutting, and on the slide before staining

Answer 3

Orientation

Question 4

Consists of 2 L-shaped strips of heavy brass or metal arranged on a flat metal plate. It can be moved to adjust the size of the mold to the size of the specimen.

Answer 4

Leuckhart’s Embedding Mold

Question 5

Blocking-out mold recommended for routine use

Answer 5

Leuckhart’s Embedding Mold

Question 6

Made up of a series of interlocking plates resting on a flat metal base. It has the advantage of embedding more specimens at a time.

Answer 6

Compound embedding unit

Question 7

Consists of a special stainless steel base mold fitted with a plastic embedding ring

Answer 7

Plastic embedding rings and base mold

Question 8

Disposable embedding mold recommended for busy routine laboratories

Answer 8

Plastic ice trays

Question 9

Three disposable embedding molds

Answer 9

A. Peel-Away disposable thin plastic embedding molds
B. Plastic Ice Trays: recommended for busy routine laboratories
C. Paper Boats

Question 10

Tissue tek is equipped with a…

Answer 10

Warm plate and a cold plate at -5ºC

Question 11

Advantages of tissue tek

Answer 11

▪ ease of use
▪ less paraffin wax needed
▪ faster embedding
▪ firmly attached tissue and holder and permanent identification

Question 12

Recommended for embedding hard tissues and for large sections of whole organs

Answer 12

Celloidin or nitrocellulose method

Question 13

In nitrocellulose method, _________ were used to control the rate of evaporation of the solvent

Answer 13

Bell jars

Question 14

the process in which tissues are first infiltrated with celloidin and subsequently embedded in paraffin mass

Answer 14

Double-Embedding Method

Question 15

used to facilitate cutting of large blocks of dense firm tissues

Answer 15

Double-embedding method

Question 16

recommended for making small sections of celloidin blocks

Answer 16

Double-embedding method

Question 17

Produces superior results for light microscopic studies (hard tissues such as undecalcified tissues)

Answer 17

Plastic (resin) embedding

Question 18

Plastic embedding is used for for high resolution light microscopy of tissue sections with what thickness?

Answer 18

thinner than the usual 4-6 um

Question 19

Balanced mixture of epoxy plastic, catalysts, and accelerators

Answer 19

Epoxy embedding plastics

Question 20

It has the disadvantage of being hydrophobic

Answer 20

Epoxy embedding plastics

Question 21

This embedding medium reduce antigenicity of embedded tissue

Answer 21

Epoxy embedding plastic

Question 22

This embedding medium may cause sensitization if absorbed by skin or inhalation

Answer 22

Epoxy embedding plastic

Question 23

Component of epoxy embedding plastics that is carcinogenic

Answer 23

Vinylcyclohexane dioxide (VCD)

Question 24

Slow epoxy plastic

Answer 24

Bisphenol A (Araldite)

Question 25

Epoxy plastic with lower viscosity and often sold as mixtures of isomers

Answer 25

Glycerol (Epon)

Question 26

Epoxy plastic with very low viscosity and infiltrates the fastest

Answer 26

Cyclohexene dioxide (Spurr)

Question 27

Introduced for electron microscopy

Answer 27

Polyester plastics

Question 28

Made up of esters of acrylic or methacrylic acid, used extensively for light microscopy

Answer 28

Acrylic plastics

Question 29

Is added to the plastic as a catalyst that decomposes to form phenyl radicals acting as active sites for the polymerization of acrylics

Answer 29

Benzoyl peroxide