HTL Laboratory Instrumentation & Equipment 3

Question 1

The numerical aperture (NA) of an objective lens directly determines the microscope's:

Accepted Answer

Resolving power

Answer

Numerical aperture determines the resolution of the objective; higher NA allows finer detail to be distinguished.

Question 2

Paraffin sections that consistently fold or wrinkle as they come off the microtome knife are MOST likely caused by:

Accepted Answer

Block temperature that is too warm

Answer

A warm paraffin block is too soft to hold its shape, causing sections to fold and wrinkle as they are cut.

Question 3

Which staining instrument component directly controls the volume of reagent dispensed onto each slide in an autostainer?

Accepted Answer

Peristaltic pump

Answer

Peristaltic pumps deliver precise, reproducible volumes of reagents to slides in automated staining platforms.

Question 4

A laboratory centrifuge showing excessive vibration during operation should FIRST be evaluated for:

Accepted Answer

Imbalanced rotor load

Answer

Imbalanced loading of the rotor is the most common cause of centrifuge vibration and must be corrected to prevent damage and injury.

Question 5

Köhler illumination is set up on a brightfield microscope primarily to:

Accepted Answer

Provide even, glare-free illumination and optimize resolution

Answer

Köhler illumination ensures uniform, focused light across the entire field of view while minimizing glare and maximizing resolution.

(HTL) Histotechnology Certification Practice Test