Microscopy Basics Lesson 1-10

Questions and Answers

What are the functions of the iris diaphragm and condenser?

The iris diaphragm regulates how much light is on the object being viewed, and the condenser focuses light into an objective as it moves up and down enhancing specimen contrast.

Name the three main objectives used on a clinical microscope.

10x, 40x, and oil immersion 100x

Explain the uses of the course and fine adjustments.

The course adjustment is used to focus with the low power objective and focusing with a high power could result in damaging the slide or the objective lens; the fine adjustment is used once the course adjustment puts the object into view to give a sharp image.

Describe the proper method of cleaning a microscope after use.

Damaged or cloudy lenses should be replaced, oculars and objectives should be cleaned with lens paper before and after use. Signup and view all the answers

How should a microscope be stored when not in use?

The stage should be all the way up, the lowest objective should be on, and it should be placed in a secure cabinet under a dust cover. Signup and view all the answers

When is oil immersion used on a slide?

After focusing with the low objective, it gives the highest magnification. Signup and view all the answers

Explain how to adjust the interpapillary distance on a distance microscope.

By adjusting the oculars together or apart until only one image is shown. Signup and view all the answers

When is the oil immersion objective used?

To view stained blood cells, tissue sections, and stained slides. Signup and view all the answers

What is the purpose of making a dioptic adjustment and how is the adjustment made?

To bring the object into sharp focus; look with the right eye and left eye closed and use the course adjustment for sharp focus, then alternate eyes and focus the knurled collar with the left eye until the image is sharp. Signup and view all the answers

How is total magnification calculated on a compound microscope?

Magnification strength times ocular strength. Signup and view all the answers

How do electron microscopes differ from light microscopes?

They offer much better quality than light microscopes and use an electron beam rather than a light source. Signup and view all the answers

When must standard precautions be used with a microscope?

-Electrical cords must be in good condition, -liquids must be away from cords. Signup and view all the answers

What is Kohler illumination and how is it performed?

Centering and aligning or focusing the light path using the field diagram. Signup and view all the answers

Why is a condenser not used in epi-fluorescence microscopes?

Because light is applied from the specimen. Signup and view all the answers

Why are electron microscopes not for routine use in the clinical lab?

They are expensive, require special training to operate, and require the use of hazardous chemicals and instruments. Signup and view all the answers

Explain how the image formed in the Transmission Electron Microscope (TEM) differs from that found in Scanning Electron Microscope (SEM).

In TEM, the electron beam is passed through the specimen, whereas in SEM, the electron beam covers the surface of the specimen. Signup and view all the answers

Explain the difference between lenses that are parfocal and those that are parcentric.

Parfocal lenses require only small changes when focusing fine adjustment, and parcentric lenses will keep the specimen centered in one objective when it is centered in the next objective. Signup and view all the answers

Study Notes

Microscope Components and Functions

The iris diaphragm controls the amount of light reaching the specimen, while the condenser focuses this light to enhance contrast.
Common magnification objectives on clinical microscopes include 10x, 40x, and oil immersion at 100x.

Focusing Techniques

The coarse adjustment is for focusing with low power objectives, while the fine adjustment sharpens the image after initial focus.
Oil immersion is utilized for high magnification, particularly after low power focusing, enhancing detail in specimens.

Microscope Maintenance and Storage

Clean only with lens paper to avoid scratching; replace any damaged or cloudy lenses for optimal viewing.
Store the microscope with the stage up, the lowest objective in place, and cover it with a dust cover in a secure cabinet.

Adjustments for Viewing

Interpapillary adjustment is done by modifying the distance between oculars until only one image is seen.
Dioptic adjustment ensures a sharp focus by alternating between eyes and fine-tuning with the knurled collar.

Total Magnification

Calculated by multiplying the objective lens magnification by the ocular lens magnification for the compound microscope.

Microscope Types and Precautions

Electron microscopes use an electron beam, offering superior quality compared to light microscopes but are costly and require specialized training.
Standard precautions with microscopes include ensuring electrical cords are undamaged and keeping liquids away from them.

Illumination Techniques

Kohler illumination aligns the light path with the specimen using the field diagram for better visualization.
In epi-fluorescence microscopes, condensers are unnecessary as the light is provided directly from the specimen.

Differences in Electron Microscopy

Transmission Electron Microscopy (TEM) utilizes electron beams through specimens, while Scanning Electron Microscopy (SEM) directs electron beams over specimen surfaces.
Parfocal lenses maintain focus across different objectives with minimal adjustment, whereas parcentric lenses keep the specimen centered as objectives change.

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Description

Test your knowledge on the fundamentals of microscopy with these flashcards. This quiz covers important components such as the iris diaphragm, condenser, and microscope objectives, providing a comprehensive review of microscopy techniques. Perfect for beginners and those looking to refresh their understanding.