PRELIM: CH11 IMPREGNATION AND EMBEDDING (2)

Bone, teeth, brain, and eyes

Which tissue group generally requires particularly careful or prolonged infiltration because it is difficult to infiltrate?

Dehydrating and clearing agents can dissolve and remove tissue fat.

Why is paraffin processing generally not recommended for fatty tissues?

Two or more changes of melted paraffin wax

After clearing, tissue is usually submerged in:

55–60°C

Routine paraffin infiltration is commonly performed in an oven or incubator maintained around:

Size and type of tissue

Which factor affects the duration and number of wax changes required for impregnation?

It reduces the time required for complete impregnation.

What effect does vacuum embedding have on infiltration time?

54–58°C

In a laboratory maintained at approximately 20–24°C, which paraffin melting point is generally appropriate?

50–54°C

If the laboratory temperature is approximately 15–18°C, which paraffin melting point range is indicated?

A higher melting point

Compared with soft tissues, hard tissues generally require paraffin wax with:

4

How many wax changes are recommended in the manual processing schedule described in the notes before final embedding?

15-minute intervals

In the manual processing schedule, the four wax changes occur at approximately:

3 hours

After the four 15-minute wax changes, the specimen is placed in fresh melted paraffin for approximately:

10% buffered formalin for 24 hours

In the example manual processing schedule, fixation uses:

70% alcohol

In the example schedule, the tissue is first dehydrated using:

6 hours

In the example schedule, 70% alcohol is used for approximately:

12 hours

The example schedule uses 95% alcohol for:

3

In the given manual schedule, the total number of changes involving 100% alcohol is:

Xylene or toluene for two 1-hour changes

The clearing stage in the example schedule uses:

It reduces time and labor while providing more consistent tissue processing.

What is the main advantage of automatic tissue processing?

Fixation, dehydration, clearing, and infiltration

An automatic tissue processor can perform which sequence?

Only about 2–3 changes of wax

Compared with manual processing, automatic processing generally requires:

Constant agitation accelerates and improves penetration.

Why does automatic processing improve tissue penetration?

12

The Elliott Bench-Type Processor contains how many individual processing steps?

10 one-liter glass beakers and 2 thermostatically controlled wax baths

The Elliott processor described in the notes contains:

To protect wax against overheating

What is the purpose of the safety cut-out switch on the wax baths?