Compound Light Microscope Quiz: Simple vs Compound Microscope

What is the total magnification when using a X10 ocular lens and a X40 objective lens on a compound light microscope?

How would replacing the condenser with a darkfield condenser impact the view in a compound light microscope?

What are photomicrographs?

What term is used to refer to the microscope when objects are observed against a bright background?

Which component in a compound light microscope impacts whether objects are seen against a dark or bright background?

If an X10 ocular lens is used with an X100 objective lens, what is the total magnification achieved?

What is the role of the eyepiece or ocular lens in a compound light microscope?

What is the resolving power of a compound light microscope?

What is one of the limitations of visible light in microscopy?

What happens when an object is observed under dark field illumination in a microscope?

Simple Microscopes

Contain only one magnifying lens
A magnifying glass is an example of a simple microscope
Images appear 3-20 times larger than the object's actual size
Leeuwenhoek's simple microscopes had a maximum magnifying power of about X300 (300 times)

Compound Microscopes

Contain more than one magnifying lens
Also referred to as compound light microscopes due to the use of visible light as the source of illumination
Usually magnify objects about 1000 times
Resolving power is approximately 0.2 µm (about 1,000 times better than the unaided human eye)
Limited by the wavelength of visible light (~0.45 µm), which determines the minimum size of objects that can be seen

Improving Contrast in Light Microscopy

Contrast improvement is essential for a clear final image
Staining is a common method to improve contrast in bright field microscopy
Dyes used for staining are organic compounds that bind to specific cellular materials
Basic dyes are positively charged and bind to negatively charged components like nucleic acids and acidic polysaccharides
Staining can, however, kill cells and distort their features

Types of Staining Procedures

Simple stain
Differential stain
Structural stains

Electron Microscopes

Enable the observation of extremely small microbes like rabies and smallpox viruses
Cannot be used to observe living organisms, as the processing procedures are lethal to cells
Use an electron beam as the source of illumination and magnets to focus the beam
Have a much higher resolving power than compound light microscopes
Come in two types: transmission and scanning electron microscopes

Learn about the differences between simple microscopes, which contain only one magnifying lens, and compound microscopes, which contain multiple lenses for higher magnification.