HT Microscopy & Image Analysis 2

Question 1

What is the purpose of using immersion oil with a 100x objective lens?

Accepted Answer

To increase the refractive index and improve resolution

Answer

Immersion oil matches the refractive index of glass, reducing light refraction loss and improving resolution at high magnifications.

Question 2

Which microscopy technique uses evanescent waves to illuminate only the region immediately adjacent to the coverslip?

Accepted Answer

Total internal reflection fluorescence (TIRF) microscopy

Answer

TIRF microscopy excites fluorophores only within ~100-200 nm of the coverslip surface using evanescent waves, giving excellent signal-to-noise for surface imaging.

Question 3

In digital pathology, what does the term 'WSI' stand for?

Accepted Answer

Whole slide imaging

Answer

Whole slide imaging (WSI) refers to digitizing an entire glass slide at high resolution for remote viewing and analysis.

Question 4

A histotechnician notices that cells appear artificially elongated on a photomicrograph taken at low magnification. This artifact is most likely due to:

Accepted Answer

Incorrect aspect ratio or pixel mapping settings

Answer

Incorrect aspect ratio settings or non-square pixel mapping in the imaging software can cause artificial stretching or compression of the captured image.

Question 5

What does numerical aperture (NA) determine in light microscopy?

Accepted Answer

The light-gathering ability and resolving power of the objective

Answer

Numerical aperture (NA = n·sin θ) determines both the light-gathering ability and the maximum resolution an objective can achieve.

(HT) Histotechnician Certification Practice Test

(HT) Histotechnician Certification Practice Test

HT Microscopy & Image Analysis 2