Microscopy and Compound Light Microscope

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Questions and Answers

What is the primary focus of microscopy in the context of animal science?

Analyzing animal behavior

Observing macroscopic organisms

Studying microscopic structures (correct)

Measuring body temperatures

Which of the following techniques is primarily used in microscopy for enhancing image resolution?

Genetic modification

Behavioral observation

Mathematical modeling

Staining (correct)

Which type of microscopy would most likely be used to explore the internal structures of cells?

Darkfield microscopy

Transmission electron microscopy (correct)

Fluorescence microscopy

Brightfield microscopy

In microscopy, what is the purpose of using high magnification?

To identify smaller cellular components Signup and view all the answers

Which of the following is a common limitation of microscopy techniques?

Resolution limits due to wavelength Signup and view all the answers

What is the primary purpose of using microscopes in the technical field?

To view samples not visible to the naked eye Signup and view all the answers

Which of the following objects would most likely require a microscope for observation?

A human hair Signup and view all the answers

In which scenarios are microscopes typically utilized?

Examining fine details of biological samples Signup and view all the answers

What kind of samples can benefit from microscopic examination?

Single-celled organisms Signup and view all the answers

What advantage does a microscope provide over regular eyesight?

It enables viewing of minute details not visible to the naked eye Signup and view all the answers

What is the purpose of a scale bar in measuring specimens?

To provide a reference for the size of the specimen Signup and view all the answers

Which of the following applications can be used to measure the size of photographed specimens using a scale bar?

Photo editing software Signup and view all the answers

What is a blood smear?

A laboratory procedure for examining blood cells Signup and view all the answers

In which scenario would a micrometer slide be particularly useful?

For measuring very small dimensions accurately Signup and view all the answers

Why might standard photo editing software not be sufficient for precise specimen measurement?

They may not support scale bar integration Signup and view all the answers

What is the primary function of red blood cells (RBCs) in the human body?

Carrying oxygen Signup and view all the answers

Which component of blood is essential for the clotting process?

Platelets (PLTs) Signup and view all the answers

Which step in blood smear preparation involves the use of an anticoagulant?

Collection of peripheral blood Signup and view all the answers

What technique is suggested for preparing a blood smear on a slide?

Using a spreader slide to push the blood Signup and view all the answers

What is necessary to do within one hour of collecting blood to avoid distortion of cells?

Perform the blood smear preparation Signup and view all the answers

What type of microscope uses one ocular lens?

Monocular compound light microscope Signup and view all the answers

Which part of the compound light microscope is responsible for adjusting the focus?

Coarse adjustment Signup and view all the answers

What type of image does a scanning electron microscope (SEM) create?

3D image of surface details Signup and view all the answers

What is the purpose of using oil with the oil immersion lens?

To increase numerical aperture Signup and view all the answers

What does the numerical aperture (NA) measure in a microscope?

Capacity to collect light Signup and view all the answers

How does the transmission electron microscope (TEM) visualize specimens?

By passing electrons through thin sections Signup and view all the answers

What is the maximum magnification power of the oil immersion lens in a compound light microscope?

1000x Signup and view all the answers

Which component of the light microscope can be adjusted to control the amount of light passing through the specimen?

Aperture Signup and view all the answers

What does the term 'working distance' refer to in microscopy?

Distance between objective lens and cover glass surface Signup and view all the answers

What is the resolution power of a microscope?

The ability to distinguish details in a sample Signup and view all the answers

Which type of lens is used in the scanning electron microscope?

Electrostatic lens Signup and view all the answers

What does the formula NA = n sinθ represent in microscopy?

Numerical aperture of the objective lens Signup and view all the answers

Which microscopes typically use stages for slide manipulation?

Light microscopes only Signup and view all the answers

What happens to the lens's numerical aperture as the angle of light increases?

It increases Signup and view all the answers

Study Notes

Microscopy

Microscopy is the technical field that uses microscopes to view samples and objects that cannot be seen with the unaided eye.
Microscopes can be classified by the number of lenses they have, such as monocular, biocular, or simple light microscopes.
Compound light microscopes are the most commonly used microscopes.

Compound Light Microscope Parts

Optical System:
- Ocular lens (eyepiece)
- Objective lens
- Nosepiece
- Head
- Eye piece tube
Mechanical System:
- Arm
- Mechanical stage
- Aperture
- Diaphragm
- Condenser
- Coarse adjustment
- Fine adjustment
- Stage controls
- Base
- Illuminator (light)
- Light switch
- Brightness adjustment

Compound Light Microscope Lenses

Scanning lens
Low power lens
High power lens
Oil immersion lens

Sliding Ruler

Used for adjusting and saving the location of a slide on the microscope stage.
Has X and Y axes.

Electron Microscopes

Scanning electron microscope (SEM): Creates a 3D image by detecting reflected electrons.
Transmission electron microscope (TEM): Creates a 2D image using electrons that pass through the sample.

Scanning Electron Microscope (SEM) vs. Transmission Electron Microscope (TEM)

Source of Illumination: Electrons used for image formation in both types of microscopes.
Visualized Cells: SEM: Specimens coated with gold, electrons reflected back to give an image of the specimen's surface. TEM: Thin sections of the specimen are used, electrons pass through the section to give an image of the internal structure of the specimen.
Images: SEM: 3D. TEM: 2D.
Lenses: SEM: One electrostatic lens with few electromagnetic lenses. TEM: One electrostatic lens with few electromagnetic lenses.
Medium: Vacuum for both.

Concepts

Resolution power: The ability of a microscope to distinguish the details of a sample.
Magnification power: The enlargement of images up to 1000 times their original size.
Working distance: The vertical distance between the front surface of the lens and the surface of the coverslip on the specimen.
Numerical aperture (NA): The ability of an objective lens to collect light. Formula: NA = n sinθ.
- n: Refractive index of the medium
- θ: Angle of light collected by the objective lens

Formula for Resolution and Magnification

Resolution (R): R = 0.6λ / NA.
- λ: Wavelength of light (approximately 0.527)
- NA: Numerical aperture
Magnification (M): M = (Power of eyepiece) × (Power of objective lens)
Total Magnification: (Power of eyepiece) × (Power of objective lens)

Example

If the maximum NA for an oil immersion lens is 1.5, the maximum possible resolution of the light microscope can be calculated using the resolution formula.
Scale bars are used to measure the size of photographed specimens within different applications.

Blood Film (Blood Smear)

A blood smear is a blood test used to examine abnormalities in blood cells.
Three components of human blood:
- Red blood corpuscles or cells (RBCs): Carry oxygen throughout the human body.
- White blood cells (WBCs): Help the human body fight infections.
- Platelets (PLTs): Important for blood clotting.

Steps of Blood Smear Preparation

Preparation of blood smear: Collection of peripheral blood, put in EDTA (anticoagulant) or finger stick blood directly onto a slide.
Fixation of blood smear: This involves using a fixative like methanol to preserve the cells' morphology.
Staining of blood smear: This step uses different stains (e.g., Romanowsky stain) to differentiate between blood cell types.

Blood Smear Preparation Equipment

Spreaders
Clean slides
Capillary tubes
Micropipette

Blood Smear Preparation Steps

Place a blood drop (2mm diameter) approximately an inch from the frosted area of the slide.
Place the slide on a flat surface and hold the narrow side of the non-frosted edge between your thumb and forefinger.
Place the smooth clean edge of a second slide (spreader slide) just in front of the blood drop.
Allow the blood to spread almost to the edges of the spreader slide.
Push the spread forward with one light, smooth, and fluid motion.

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Description

Explore the fascinating world of microscopy through this quiz. Test your knowledge about the various types of microscopes, their parts, and functions. Gain insights into the essential components that make up the compound light microscope and how it operates.