What is a Microscope?

A microscope is a tool that magnifies small objects so you can see detail the naked eye simply can't pick up. In a school or lab setting, that usually means looking at cells, tissue samples, microorganisms, crystals or fibres, anything too small or too fine to study on its own.

How does a microscope work?

Most microscopes used in schools and labs are optical microscopes. Light passes through or reflects off the specimen, and a set of lenses bends that light to make the image bigger. You look through the eyepiece, which magnifies the image again on top of what the objective lens has already done, so the two work together to reach the final magnification.

The main parts of a microscope

Every optical microscope has a few parts in common, even if the exact design varies. The eyepiece is what you look through, usually magnifying 10x on its own. The objective lenses sit just above the specimen and typically offer a few different magnification levels you can rotate between. The stage holds the slide in place, and a light source or mirror underneath illuminates the specimen from below. Focus knobs raise and lower the stage, or the lens tube, until the image is sharp.

Types of microscopes you'll find in a school or lab

Monocular microscopes have a single eyepiece and suit most classroom and general lab work. Binocular microscopes use two eyepieces, which is easier on the eyes over a long session and tends to be the more common choice for university and research labs. Trinocular microscopes add a third port for a camera, handy when you want to project or record what's on the slide. Stereo microscopes work differently again, giving a lower magnification 3D view of larger specimens like insects, circuit boards or rock samples, rather than thin slide mounted samples. Digital microscopes replace the eyepiece with a screen, or connect straight to a computer.

Electron microscopes and scanning probe microscopes exist too, used for very high magnification research work, but they're specialised equipment well beyond typical school and lab budgets. For help matching a type to your actual needs, our guide on how to choose a microscope goes into more detail.

What can you actually see under a microscope?

With a standard optical microscope, you can see plant and animal cells, bacteria, pond life, blood cells, fibres, crystals and thin sections of tissue, generally anything that fits on a microscope slide. Magnification on the optical microscopes used in schools and labs typically runs from about 40x up to 1000x, which covers the vast majority of biology, general science and quality control work. If you're working with prepared or blank slides, our guide to microscope slides covers how they're set up and used.

Frequently asked questions

What's the difference between a monocular and binocular microscope?
A monocular microscope has one eyepiece, which is fine for most classroom use and usually the more affordable option. A binocular microscope has two eyepieces, more comfortable for anyone spending long stretches at the microscope, common in university and research settings.

How powerful does a microscope need to be for school biology?
Most school biology work is comfortably covered by 40x to 400x magnification. Higher magnifications, up to 1000x, are useful for looking at smaller structures like bacteria, but aren't essential for a typical curriculum.

Can I see viruses with a normal microscope?
No. Viruses are too small to see with a standard optical microscope. You would need an electron microscope for that, which is specialised, expensive equipment well outside what schools and most labs use day to day.

If you're buying your first microscope for a classroom or home lab, our Microscope Student Kit is one of our most popular starting points, covering 40x up to 640x magnification. Browse our full range of microscopes, from monocular classroom models to binocular, trinocular, stereo and digital options, or get in touch if you need help matching a microscope to your school or lab's budget and curriculum.