The Microscope- compound microscope diagram

The Microscope

Concerns

The microscope is an optical tool that can be used to amplify very small objects, such as animal cells and minerals. Microscopes have allowed us to see things that we cannot see with our naked eyes, making major discoveries in many fields of science, especially biology.
Microscopes use a combination of different lenses to create a larger image. There are different types of microscopes, but the original and most commonly used one is an optical microscope. Optical microscopes shine through a sample to create a thickened image. The human eye has a resolution of about 10 -4 meters and we are unable to actually see small things without assistance. The first way to magnify small objects was using a single convex lens. These offered only limited magnification, much smaller than simple composite microscopes that use multiple lenses at once.

Students with microscope

Invention

The invention of the microscope is unknown. It is believed that Zacharias Janssen and his father Hans were responsible for making the first mixed microscope in the Netherlands in the latter part of the 16th century. Galileo is sometimes listed as the inventor, but this is unlikely to be true. In 1665 Robert Hooke produced a very influential book called Microstria in which he drew images of objects that cannot be seen with the naked eye. It was in this book that Hooke coined the term 'cell' as an organic building block. The microscope is incredibly important in furthering our knowledge of the world, which is so small that it cannot be seen with our naked eyes. Microscopes have led to the discovery of bacteria, Anton van Leeuwenhoek first described and wrote about them in the 17th century.

Photography gave a new edge to microscopy, allowing scientists to take pictures they saw through the eyepiece. This allowed them to easily share their findings with colleagues and people. In modern times, scientists now use electron microscopes that allow for much higher levels of magnification than optical microscopes.

Image from electron microscope

Types of microscopes

Optical microscope - used to view small structures and objects using visible light.

Image of optical microscope

Fluorescence Microscopes - Similar to optical microscopes, but uses fluorescence to increase resolution.

Image of fluorescence microscope

Electron microscope - Uses electrons instead of light can magnify up to 10,000,000 X.

Image of Electron microscope

Scanning Probe Microscope - Used at the atomic level to produce images of a surface.

Diagram representation of scanning probe microscope

X-ray microscope - uses X-rays in place of visible light and is used to look inside small objects and structures.

image of x-ray microscope

Light microscope or optical microscope

Components of optical microscope:

Objective:

the first lens light passes through after the specimen. The objective collects the light from the specimen and focusses it to a point inside the body tube. The objective lens is responsible for producing the magnified image, and can be the most expensive component of the light microscope.

eyepiece:

the lens light passes through before getting to your eye. The eyepiece magnifies the image formed by the objective so you can see your sample.

specimen:

whatever you are trying to study! Depending on the microscope, the sample may need to be translucent to allow enough light through it for you to see.

Condenser:

a lens placed before the specimen in order to collect and focus light onto the sample in order to help create images. Coverslip: coverslip thickness (usually 0.17 mm)