Unit 1- Quiz 2-Microscopy Quiz for Biotechnology

Why is immersion oil used with the 100× objective lens in a brightfield microscope?

• To disinfect the slide

• To reduce heat loss

• To match the refractive index of glass and improve resolution

• To magnify the image further

In a pharmaceutical QA/QC lab, a sample under a brightfield microscope appears dim and lacks contrast. What is the first adjustment a trained technician should try?

• Change objective lens

• Increase rheostat intensity

• Open the diaphragm below the condenser

• Remove the slide and clean it

Which microscopy method is preferred when constructing a 3D view of a thick specimen such as a biofilm?

• Confocal microscopy

• Fluorescence microscopy

• Darkfield microscopy

• Brightfield microscopy

Which technique allows for signal amplification and more sensitive detection in fluorescence microscopy?

• Brightfield imaging

• Indirect immunofluorescence assay (IFA)

• Direct immunofluorescence assay (DFA)

• Oil immersion microscopy

Which microscopy technique is ideal for viewing internal details of live, unstained cells?

• Brightfield

• Phase-contrast

• Darkfield

• Confocal

Why is phase-contrast microscopy preferred over brightfield for examining live cell cultures?

• No light needed

• No training required

• Better contrast for unstained cells

• Uses fluorescent dyes

What is the main function of the condenser lens in brightfield microscopy?

• To magnify the image

• To clean the light source

• To focus light onto the specimen

• To alter image color

In fluorescence microscopy, what is the role of the excitation filter?

• It blocks visible light

• Directs UV to the eye

• Filters to a specific excitation wavelength

• Removes noise from camera

Which microscopy technique gives a pseudo-3D effect without fluorescence or staining?

• Confocal

• Phase-contrast

• DIC

• Rheostat imaging

Which issue limits resolution at high magnification and how is it mitigated?

• Chromatic aberration

• Light scattering in air, use oil

• Lens vibration

• Condenser misalignment