The history, development and use of the light and electron microscope

Authors Avatar

The history, development and use of the light and electron microscope

History of light microscope

Observing objects in detail greater than the naked eye was very interesting to people at early stage. This led to the construction, in the 16th century, of a magnifier composed of a single convex lens, and this, in turn, led to the eventual development of the microscope.

The most famous early pioneers in the history of the microscope are Digges of England and Hans and Zcharias Janssen of Holland.

But it was Antony van Leeuwenhoek who became the first man to make and use a real microscope.

Leeuwenhoek ground and polished a small glass ball into a lens with a magnification of 270X, and used this lens to make the world's first optical microscope.

Because it had only one lens, Leeuwenhoek's microscope is now referred to as a single-lens microscope. Its convex glass lens was attached to a metal holder and was focused using screws.

The light microscope system was invented in the seventeenth century. This type of microscope incorporates more than one lens so that the image magnified by one lens can be further magnified by another.

Today, the term "microscope" is generally used to refer to this type of compound microscope.

Since its invention, the light microscope has made tremendous progress and help figure out many biological molecules. Using a light microscope that he had built himself, the 17th-century Englishman Robert Hooke discovered the fact that living things are composed of cells.

The 19th century saw dramatic progress in the development of the microscope, some scientist experimented and developed further such as Carl Zeiss, who made significant effort to the manufacture of microscopes, Ernst Abbe, who carried out a theoretical study of optical principles, and Otto Schott, who conducted research on optical glass.

(I searched these information form website: http://home.att.net/~gallgosp/scihist.htm)

Development of Electron Microscope

Electron microscope was developed in the  and has allowed great advances in the . The advantage of an electron beam is that it has a much smaller , which allows a higher  - the measure of how close together two things can be before they are seen as one. Light  allow a resolution of about 0.2 , whereas electron microscopes can resolutions below 1 .

Electron Microscopes were developed due to the limitations of Light Microscopes which are limited by the physics of light to 500x or 1000x magnification and a resolution of 0.2 micrometers. In the early 1930's this theoretical limit had been reached and there was a scientific desire to see the fine details of the interior structures of organic cells (nucleus, mitochondria...etc.). This required 10,000x plus magnification which was just not possible using Light Microscopes.

Join now!

There are two types of electron microscope Transmission and Scanning.

How the electron microscope has given us a greater understanding of cellular structure.

The small size of cells and the lack of contrast between their structural components are two major problems that have to be overcome. Microscopes of a variety of different kinds can be used to produce a magnified image of cells.

There are many microscopes but Electron Microscope has given us a greater understanding of cellular structure.

Electron Microscope allows the user to determine the internal structure of materials (specimen), either of biological or ...

This is a preview of the whole essay

Here's what a star student thought of this essay

Avatar

The grammar and punctuation were fine. The spelling was awful. Such mistakes included "hevy" instead of "heavy". These mistakes can be avoided by proof reading (many times) and such mistakes can cost the student marks especially if there is a mark for QWC (quality of written communication). The technical terms used were appropriate for this level and a glossary would have highlighted that the student understood the topic even more. The typical layout of the work was followed here, and it is highly recommended as it is the simplest and easiest way to structure the work and for the examiner to identify the areas for awarding marks more easily.

The level of analysis was fine for most of the piece of work. The basics and foundations of the understanding of the microscopes is very evident but the student needs to show that they understand more than the textbook surface value. They need to show that they actually understand why the microscope works in the way it does and the significance of this in relation to its usage. Such 'extra' knowledge will really gain the student more marks as it goes beyond the syllabus (although such 'extra' knowledge may vary from exam board to exam board). The appropriate conclusions were reached and their response was clear although lacking in detail.

The student shows a good understanding of the topic and answers the set question in a logical and clear way. However, I feel the student has 'glossed over' too many key points regarding the physics behind the microscopes. For example, how they (e.g. TEMs) work is implied and for me, it was not explicitly addressed. Whilst the question does not directly address the background behind it, it is safer to assume that in exploring its usage, the student needs to also mention how they work. Having said this, the student does not lack understanding in the 'wider knowledge' of the topic. They now need to focus on adding in specifics to similar works next time to ensure they get higher marks.