24 Questions
What is the most common type of microscope?
Light microscope
What is the main advantage of phase contrast microscope?
It allows for viewing of living cells and cell division
What type of microscope is used to examine blood cells?
Dark field microscope
What is the name of the microscope that uses a special condenser and objective with a diaphragm to scatter light?
Dark field microscope
What type of microscope is used to study living cells without killing them by staining?
Phase contrast microscope
What is the main difference between a simple microscope and a compound microscope?
Design and functionality
What type of microscope is used to view the structure of cells clearly?
Dark field microscope
What is the purpose of a microscope in a medical laboratory?
To examine samples
What is the purpose of fixation in sample preparation?
To stabilize the cell and preserve its structure
What is the main difference between TEM and SEM?
The electron beam is scanned across the surface of the sample in SEM
What is the purpose of sputter coating in sample preparation?
To apply a thin layer of conductive material to the sample
What is a disadvantage of using an electron microscope?
It is very expensive to buy and maintain
What is the primary function of a stereo microscope?
To exam insects and help in anatomical dissection
What is the purpose of cryofixation in sample preparation?
To rapidly freeze the sample in liquid nitrogen or liquid helium
What is a digital microscope?
A traditional microscope that uses a digital camera to output an image to a monitor
What is the most frequently used chemical in chemical fixation?
Glutaraldehyde
What is a disadvantage of the microscope type discussed by Hayder Ahmed?
Limited colors (just black and white)
What type of light is used in fluorescence microscopy?
Ultra-violet light
What is the purpose of the special optical filters in fluorescence microscopy?
To absorb colors at all wavelengths, except the wavelength of the dye used
What is the advantage of electron microscopes over light microscopes?
They have a greater resolving power
What lenses are used in electron microscopes?
Electromagnetic and/or electrostatic lenses
Why do electron microscopes have a greater resolving power than light microscopes?
Because they use a shorter wavelength
What is the maximum magnification possible with modern electron microscopes?
About two million times
What is the function of the fluorescent dye in fluorescence microscopy?
To make the sample parts glow
Study Notes
Types of Microscopes
- Light microscope: uses light to pass through the sample to produce an image
- Simple microscope: oldest design, magnifies small samples
- Compound microscope: commonly used in medical laboratories
Phase Contrast Microscope
- Enhances contrast of transparent and colorless objects by influencing light's optical path
- Allows for examination of living cells and cell division without staining
Dark Field Microscope
- Uses a special condenser and objective with a diaphragm to scatter light from cells
- Cells appear bright on a dark background
- Applications: viewing blood cells, bacteria, and cell structure
- Advantages: simple to use, inexpensive
- Disadvantages: limited to black and white colors
Fluorescence Microscope
- Uses fluorescence and phosphorescence to study properties of substances
- Uses ultra-violet light to activate specific parts of the sample
- Fluorochrome dye is used to make the sample glow
- Special optical filters absorb all wavelengths except the dye used
Electron Microscope
- Uses a beam of electrons to create an image of the specimen
- Capable of higher magnifications and greater resolving power than light microscopes
- Types:
- Transmission Electron Microscope (TEM): electron beam passes through the sample
- Scanning Electron Microscope (SEM): electron beam scans the surface of the sample
- Disadvantages: expensive, difficult to use
Sample Preparation for Electron Microscope
- Fixation: stabilizes the cell using chemical or cryofixation methods
- Dehydration
- Embedding
- Sectioning
- Staining
- Freezing
- Sputter Coating
Stereo Microscope (Dissecting Microscope)
- Designed for low magnification to observe the sample using light
- Used for examining insects and anatomical dissection
Digital Microscope
- Traditional microscope that uses a digital camera to output an image to a monitor
Identify and describe different types of microscopes used in laboratory settings, including light, phase contrast, dark field, fluorescence, electron, and stereo microscopes.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
