Analysing Cells

Edited by Jamie (ScienceAid Editor), Administrator, Taylor (ScienceAid Editor)

In order to make all of the discoveries explained in cell structure, scientists first needed to use a variety of techniques. These are all explained on this page.

Ad

Electron Microscope

An electron microscope is a very expensive and a very large piece of equipment that is very different to a light microscope you will have used in the lab. It is capable of magnifications up to millions of times (compared to hundreds with a light microscope).

Was this helpful? Yes | No | I need help

There are two types of electron microscopes:

  1. 1
    The transmission electron microscope (TEM).
    The TEM works by passing electrons through a specimen that is no more than 1µm (one micrometer) thick. The electrons in the specimen are diffracted and the electrons are then picked up by a fluorescent screen.
    Advertisement
    Was this step helpful? Yes | No | I need help

  2. 2
    Scanning electron microscope (SEM).
    The SEM requires a mould to be made of the specimen using a heavy metal. Electrons are then reflected off of this sample. The advantage of the SEM is that it creates more 3D images, but the resolution and magnification is less.
    Was this step helpful? Yes | No | I need help

    Advertisement

You can see some examples of what several organelles look like under an electron microscope if you scroll down

Differential Centrifugation

This is a method to separate different organelles of a cell so they can be analyzed, perhaps to look at under an electron microscope.

diagram of preparation of a sample for differential centrifugation

The first image shows a sample that has been cut up into smaller pieces in an ice-cold buffer solution. This solution maintains the pH so that enzymes will not denature, and the ice prevents any of the enzymes breaking down newly exposed parts of the cell. In the second image you can see the sample being homogenized; the sample is put into a homogenizer (a bit like a blender) which breaks up the cells.

Was this helpful? Yes | No | I need help

diagram of a sample being spun in a centrifuge

The mixture is then filtered to remove debris and poured into test tubes that are placed in a centrifuge where it is spun at very high speeds. The most dense material forms a pellet at the bottom of this sample (probably the nucleus). A liquid sitting on top of the pellet also forms. This is called the supernatant. Once it has been separated, the supernatant can then be spun to separate the next densest material.

Was this helpful? Yes | No | I need help

Cell Differentiation

Differentiation means to be able to tell the difference between different things. It is important to be able to do this when analyzing cells, so you know what organelles you are looking at. For information on them, see cell structure.

Was this helpful? Yes | No | I need help

Nucleus Rough Endoplasmic Reticulum Golgi Body
nucleusem.jpg
rerem.jpg
golgiem.jpg
Mitochondrion Chloroplast Vacuole
mitoem.jpg
chloroem.jpg
vacuole.jpg

Comments

ScienceAid welcomes all comments. If you do not want to be anonymous, register or log in. It is free.




Jamie
Featured Author
166 Articles Started
1,267 Article Edits
42,900 Points
Jamie is a featured author with ScienceAid. Jamie has achieved the level of "Captain" with 42,900 points. Jamie has started 166 articles (including this one) and has also made 1,267 article edits. 9,600 people have read Jamie's article contributions.
Jamie's Message Board
Jamie: Hi, my name is Jamie.
Jamie: Can I help you with your problem about "Analysing Cells"?
 

Article Info

Categories : Cell

Recent edits by: Administrator, Jamie (ScienceAid Editor)

Share this Article:

Thanks to all authors for creating a page that has been read 7 times.

Do you have a question not answered in this article?
Click here to ask one of the writers of this article
x

Thank Our Volunteer Authors.

Would you like to give back to the community by fixing a spelling mistake? Yes | No