Microscopy and Microscope Parts

Flashcards covering types of microscopy, compound microscope parts, magnifications, light control components, and operating procedures.

What is microscopy?

Microscopy is the use of a microscope to view objects and structures too small to be seen with the naked eye, enabling the study of cells, tissues, and microorganisms in detail.

What is the light source used in light microscopy, and why is it most commonly used?

LED (light emitting diode): most commonly used as it runs cool, lasts a long time, and gives bright white light.

What is the light source used in electron microscopy?

AEB (accelerated electron beam).

How do light microscopy and electron microscopy differ regarding the state of the specimens used?

Light microscopy uses live, unstained/stained specimens (e.g., bacteria, parasites), whereas electron microscopy uses dead/fixed specimens (e.g., virus).

How do light microscopy and electron microscopy compare in terms of cost and usage settings?

Light microscopy is less expensive and routinely used in clinical laboratory settings, while electron microscopy is more expensive and housed in specialized laboratories or research institutions.

What are the key characteristics of bright-field microscopy?

It features a bright or white background with a dark or colored specimen and is the most common type of light microscopy used in laboratories.

What are the characteristics of dark-field microscopy?

It features a dark or black background with a bright or glowing white specimen.

When is fluorescence microscopy used?

It is used for specimens that glow on their own or specimens labelled with fluorophores.

What type of specimens is phase-contrast microscopy useful for viewing?

Live transparent biological specimens.

What type of specimen is polarizing microscopy best suited for?

Viewing crystals in a specimen (e.g. urine).

What is confocal microscopy and what are its primary fields of application?

An advanced microscope that produces very clear and detailed images; often used in cell biology, neuroscience, developmental biology, and pathology to study fine structures.

What are the primary characteristics of a Transmission Electron Microscope (TEM)?

It provides 2D images that define inner details and organelles one by one.

What are the primary characteristics of a Scanning Electron Microscope (SEM)?

It scans the surface level to create a detailed, 3D image of the outside shape and texture of the cell.

What is a compound microscope?

A type of light microscope with more than one lens and its own light source, containing ocular lenses in binocular eyepieces and objective lenses in a rotating nosepiece.

What is the function, magnification, and location of the ocular lenses / eyepiece?

Provides FURTHER magnification at $10\times$ magnification and is located at the top of the microscope.

What is the primary role of objective lenses in a microscope?

Provides INITIAL magnification as they are closer to the specimen.

What is the color indicator and magnification of the scanner objective?

Color: Red; Magnification: $4\times$.

What is the color indicator and magnification of the low power objective (LPO)?

Color: Yellow; Magnification: $10\times$.

What is the color indicator, magnification, and usage note for the high power objective (HPO)?

Color: Blue; Magnification: $40\times$; used for detailed observations.

What is the color indicator, magnification, and requirement for the oil immersion objective?

Color: White/Black; Magnification: $100\times$; requires immersion oil for clarity.

What is the formula for calculating total magnification?

$$\text{Total magnification} = \text{magnification of the eyepiece} \times \text{magnification of the objective}$$

What is the function of the light source in a compound microscope?

It is a built-in lamp that provides illumination.

What is the function of the iris diaphragm?

A part of the microscope that adjusts the amount of light passing through the condenser; it also helps control the contrast and resolution.

What is the function of the condenser?

It focuses and concentrates the light on the specimen.

What is the description and purpose of the base of a microscope?

Provides support for the microscope; it should be large and solid enough to allow the microscope to stand by itself.

What is the function of the arm of a microscope?

Supports and holds the magnifying adjustment system; it can be used as a handle for carrying the microscope.

What is the stage on a microscope?

It is the platform where the slide is placed for examination.

What is the function of the stage control knobs?

Allow precise movement of the slide along the x-axis (left and right) and y-axis (forward and backward).

What is the function of the body tube?

Connects the eyepiece to the objective lenses; ensures the correct alignment of optical components.

What is the function of the coarse adjustment knob?

Moves the stage or body tube up and down for general focusing; used primarily with low power objectives.

What is the function of the fine adjustment knob?

Allows precise focusing by making small adjustments; used with high power or oil immersion objectives.

What is the nosepiece and where is it located?

It is located at the end of the body tube for holding the objectives.

What is the head of a microscope?

The upper part that holds the ocular lens and connects to the body tube.

Why is it recommended to use only the fine adjustment knob beyond the low power objective (LPO)?

Beyond LPO, using only the fine adjustment knob avoids slide and objective breakage.

What three conditions must be met after finishing use of the microscope?

1. The cord is unplugged and neatly coiled.
2. The stage is lowered.
3. The LPO is set in place.