Processing Flashcards

Question

Infiltrating and embedding medium should be:

Answer 1

``` Soluble in processing fluids Suitable for sectioning and ribboning Molten between 30°C and 60°C Translucent or transparent; colorless Stable Homogeneous Capable of flattening after ribboning Nnon-toxic Odorless Easy to handle ```

Answer 2

Process by which tissues are first embedded with supporting medium, gelatin or agar, then embedded a second time with paraffin

Answer 3

Process by which tissues are first embedded or fully infiltrated with a supporting medium such as agar or nitrocellulose, then infiltrated/embedded a second time with wax

Answer 4

Practice of embedding wax infiltrated tissues in another wax, modified to provide improved tissue support and sectioning qualities.

Answer 5

Polycrystalline mixture of solid hydrocarbons Two thirds the density and slightly more elastic than dried protein Melting points which range from 39°C to 68°C Processed in short time Serial sections easily obtained Most staining done easily

Answer 6

Polycrystalline mixture of solid hydrocarbons | Two thirds the density and slightly more elastic than dried protein

Answer 7

Prolong heating of paraffin wax at high temperatures or use micro-crystalline wax

Answer 8

Add stearic acid

Answer 9

Add spermaceti or phenanthrene

Answer 10

Slow process, takes weeks Doesn't produce sections as thin as paraffin embedding Section cutting is done wet Sections stored in ethanol Staining done on free floating sections Processing done without heat, avoid heat produced artifacts Immunophenotyping of lymphoid and non-lymphoid cells

Answer 11

Slow process, takes weeks Doesn't produce sections as thin as paraffin embedding Section cutting is done wet Sections stored in ethanol Staining done on free floating sections Processing done without heat, avoid heat produced artifacts

Answer 12

Produce single block of friable or multiple tissue fragments First step in double embedding Used for frozen sections

Answer 13

Best for frozen sections of formalin-fixed unprocessed tissue Sucrose added before tissue is frozen

Answer 14

``` Dehydration and clearing not needed Sections cannot be placed in water bath Lipids are not removed, requires long periods of infiltration Some enzymes will remain active Tissue blocks must be chilled in fridge ```

Answer 15

``` Best for undecalcified bone Infiltration done after dehydration Cut with glass knives Can be used with some enzyme stains Do not adhere to glass slides well ```

Answer 16

Best for electron microscopy Very thin sections obtained Diamond knife: 60-90 nm thick Glass knife: 0.5 microns thick

Answer 17

Low temp: -structural elements of tissue stabilized -prolonged processing times due to high viscosity and low diffusion High temp: -cause tissue shrinkage and hardening -may produce artifacts Mild heat, 37°C to 45°C, during dehydration and clearing reduces processing times, but may increase shrinkage

Answer 18

Low temp: -structural elements of tissue stabilized -prolonged processing times due to high viscosity and low diffusion High temp: Mild heat, 37°C to 45°C, during dehydration and clearing reduces processing times, but may increase shrinkage

Answer 19

Vacuum applied during dehydration, clearing and infiltration improves quality of processing