Microscopy Flashcards

Questions and Answers

What are the 4 types of Light Microscopes?

Fluorescence Microscope (correct)

Dark-field Microscope (correct)

Phase contrast Microscope (correct)

Bright-field Microscope (correct)

What is a Brightfield Microscope?

A microscope that allows light rays to pass through a slide/specimen and then through various lenses to the eye.

Microscopes are very expensive and must be handled with care.

True

How should microscopes be transported?

With one hand on the arm and the other hand under the base. Signup and view all the answers

What are the microscope parts and their functions?

<ol> <li>Arm - all other parts are attached to it, 2. Base - bottom, 3. Stage - platform that holds the slide, 4. Mechanical stage - device used to clamp slides, 5. Light source - provides illumination, 6. Voltage control - varies the intensity of light, 7. Lens system, 8. Focusing knobs, 9. Ocular adjustment.</li> </ol> Signup and view all the answers

What are the three lens systems in a microscope?

Condenser Signup and view all the answers

What does total magnification equal?

Ocular magnification X Objective magnification Signup and view all the answers

What are the two focusing knobs?

Coarse adjustment and Fine adjustment. Signup and view all the answers

Describe the ocular adjustment.

To see one image, pull apart or push together the oculars, and use the diopter adjustment to focus each eye. Signup and view all the answers

Define resolution.

The ability to distinguish two adjacent points as separate objects. Signup and view all the answers

Resolution is a function of what three things?

Numerical aperture, Wavelength of light, Design of condenser. Signup and view all the answers

What is the optimum resolution of the best microscope with the oil immersion lens?

0.2 micrometer Signup and view all the answers

How to increase resolution?

<ol> <li>Use a blue or green filter, 2. Raise the condenser, 3. Open the diaphragm, 4. Use immersion oil.</li> </ol> Signup and view all the answers

What is numerical aperture (NA)?

The measure of a lens' ability to capture light coming from a specimen. Signup and view all the answers

What is the limit of resolution?

D = Wavelength / (NA condenser + NA of objective lens) Signup and view all the answers

What does parfocalization mean?

The objects should stay in focus when moving between objectives. Signup and view all the answers

Oil has the same refractive index as what?

Glass Signup and view all the answers

Study Notes

Light Microscopes

Four types of light microscopes: Bright-field, Dark-field, Phase contrast, and Fluorescence.
Bright-field microscope: Allows light transmission through specimens to magnify and visualize objects.

Microscope Care and Transport

Microscopes are costly and require careful handling.
Transport using one hand on the arm and the other under the base for stability.

Microscope Parts and Functions

Arm: Supports all microscope components.
Base: Provides stability as the bottom part.
Stage: Platform for holding slides.
Mechanical stage: Clamps slides and facilitates movement.
Light source: Illumination component located in the base.
Voltage control: Adjusts light intensity; lower settings prolong lamp life.
Lens system: Comprises ocular, objective, and condenser lenses.
Focusing knobs: Includes coarse and fine adjustment knobs.
Ocular adjustment: Aligns eyepieces to create a single image.

Lens Systems

Ocular lens: Eye piece with 10X magnification and multiple lenses.
Objective lens: Four options on the nosepiece—Scanning (4X), Low power (10X), High Dry (40X), Oil immersion (100X).
Condenser lens: Located beneath the stage, it collects and directs light for uniform illumination.

Magnification and Resolution

Total magnification calculated as ocular magnification times objective magnification.
Resolution defines the clarity to distinguish between two separate points.

Factors Affecting Resolution

Influenced by numerical aperture, wavelength of light, and condenser design.
Best resolution attainable with oil immersion lens is 0.2 micrometers.

Improving Resolution

Utilize blue or green filters to reduce wavelength and enhance resolution.
Elevate condenser to maximize light entry.
Open diaphragm for increased numerical aperture.
Apply immersion oil between slide and 100X objective for optimal clarity.

Numerical Aperture and Limits of Resolution

Numerical aperture (NA) measures lens light-capturing ability, improves with oil usage and higher objectives.
Limit of resolution defined by the formula: D = Wavelength / (NA condenser + NA of objective lens).

Parfocalization

Refers to the ability of the microscope to maintain focus when switching between objective lenses.

Refractive Index of Oil

Oil matches the refractive index of glass, preventing light diffraction and loss, ensuring sharper image quality.

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Description

Test your knowledge on different types of light microscopes with this flashcard quiz. Learn about brightfield, dark-field, phase contrast, and fluorescence microscopes. Perfect for students in biology or microscopy courses!