HT Microtomy & Sectioning Techniques 3

Question 1

During cryostat sectioning, tissues exhibit excessive tearing. Which adjustment is most appropriate?

Accepted Answer

Raise the cryostat cabinet temperature closer to 0°C

Answer

Fatty or soft tissues tear when too cold; raising the cryostat temperature (toward –10°C from –25°C) softens the tissue enough for clean cutting.

Question 2

The clearance angle on a microtome knife is defined as the angle between:

Accepted Answer

The bevel face and the vertical plane of the block

Answer

The clearance angle is the angle between the bevel face of the knife and the vertical face of the tissue block, determining how freely sections pass under the knife.

Question 3

Which embedding medium is most commonly used for sectioning unfixed, fresh brain tissue to preserve enzyme activity for histochemistry?

Accepted Answer

Optimal cutting temperature (OCT) compound

Answer

OCT compound is the standard cryostat embedding medium for fresh tissue enzyme histochemistry because it supports tissue without chemical fixation.

Question 4

A 'venetian blind' artifact in paraffin sections (alternating light and dark lines parallel to the cut) is caused by:

Accepted Answer

A nick in the knife edge

Answer

A nick or chip in the knife edge creates a streak or venetian-blind pattern running the full length of each section.

Question 5

When sectioning decalcified bone, which knife profile and clearance angle combination is most appropriate?

Accepted Answer

Plano-concave knife, 5–10° clearance

Answer

A plano-concave knife with a 5–10° clearance angle provides the balance of support and sharpness needed for moderately hard decalcified bone.

(HT) Histotechnician Certification Practice Test

(HT) Histotechnician Certification Practice Test

HT Microtomy & Sectioning Techniques 3