Microscopes

Microscope

A scientific instrument used to make very small objects appear much larger.

Purpose of a microscope

To study cells, microorganisms, tiny structures in plants and animals, and materials too small to see with the naked eye.

Simple microscope

A microscope with one lens that slightly magnifies objects, similar to a magnifying glass.

Compound light microscope

A microscope that uses multiple lenses and light to magnify specimens. Commonly used in schools.

Electron microscope

A microscope that uses electrons instead of light to produce much higher magnification than a light microscope.

Digital microscope

A microscope connected to a computer or screen that can take photos and videos.

Scanning Electron Microscope (SEM)

Produces detailed 3D images of the surface of objects.

Transmission Electron Microscope (TEM)

Produces highly magnified images showing structures inside cells.

Eyepiece lens

The lens you look through.

Objective lens

The lens that magnifies the specimen.

Stage

The platform that holds the microscope slide.

Stage clips

Hold the slide in place.

Coarse focus knob

Moves the stage quickly to bring the specimen into focus. Only used on low power.

Fine focus knob

Sharpens the image. Used on all magnifications, especially medium and high power.

Arm

Supports the microscope and is used when carrying it.

Base

The bottom support of the microscope.

Light source

Shines light through the specimen.

Field of view

The amount of the specimen you can see through the microscope.

Effect of increasing magnification

Field of view decreases and image detail increases.

Effect of decreasing magnification

Field of view increases and you can see more of the specimen.

Magnification

How many times larger an image appears compared to its actual size.

Total magnification formula

Total magnification = Eyepiece lens × Objective lens.

Lowest power objective lens

Usually 4×.

First step when focusing

Start with the lowest power objective lens.

Coarse focus knob safety rule

Never use it on medium or high power because it can break the slide or damage the lens.

Lens care

Never touch the lenses with your fingers. Clean them with lens paper.

Microscope carrying method

Carry the microscope using the arm and base.

Robert Hooke

Early scientist who helped develop the compound light microscope and was one of the first to observe cells.

1600s

Simple microscope first used.

1900s

Electron microscope invented.