Expt002 : Electrophoresis of a mixture of DNA fragments

The aim of this experiment is to see how a mixture of linear pieces of DNA migrates on an agarose gel.

Method

Several samples of DNA are provided in Expt002.

Load the experiment into the sample tubes.

Transfer some of the DNA from Sample 1 to a reaction tube.

You are now ready to run the gel.

Click 'Agarose Gel Electrophoresis' in the BioLab toolkit to use this method. The reaction tubes and the DNA that you put into one tube are visible on the screen.

Load some of your DNA into one of the wells at the top of the gel - by clicking and dragging it from the reaction tube.

As soon as you let go of the mouse button over one of the wells, the DNA will be run in that track of the gel.

Result and Discussion

You should see something like this,
i.e. several bands.

The mixture of DNA is separated by electrophoresis in the agarose gel. This is because the smallest pieces of DNA migrate further and the largest pieces migrate less.

If we know the sizes of these DNA fragments, we can use them as size markers. They can be used to estimate the sizes of some unknown pieces of DNA.

Here are the sizes, in base pairs (bp) of these pieces of DNA.

Band	Size (bp)
1	2500
2	2000
3	1600
4	1200
5	800
6	600
7	400

Your turn

Return to BioLab, by clicking on the button "Return to BioLab" or the X at the top righ corner of the window.

Expt002 contains 7 more DNA samples. Each sample contains just one piece of DNA. Run them on the gel, alongside sample 1, and estimate their sizes, e.g. Sample2 is 600-800 bp

Click here to check your answer