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									Gel Electrophoresis

What is Gel Electrophoresis?
Gel electrophoresis separates molecules on the basis of their charge and size. The charged macromolecules migrate across a span of gel because they are placed in an electrical field. The gel acts as a sieve to to retard the passage of molecules according to their size and shape.

 One of the basic tools of modern biotechnology

is gene splicing.
 This is the process of removing a functional

DNA fragment ( a gene) from one organism and combining it with the DNA of another organism to study how the gene works.
 The desired result is to have the new organisms

carry out the expression of the gene that has been inserted.

Restriction Enzymes
 The ability to cut and paste DNA

predictably is due to the use of restriction enzymes.  They were first identified in and isolated from the bacteria that use them as a natural defense mechanism to cut up the invading DNA of bacteriophages – viruses that infect bacteria.  They are named for the

The negatively charged particles move toward the positive electrode while the the positive charge particles move toward the negative electrode.

How does electrophoresis work? • The gel is made from agar • DNA is a negative molecules • Molecules sort based on •Charge •Size •shape

What is agar?
Agar comes from sea weed. What is it used for?

The gel is 1% agarous and has no electrical charge.

How does it work?
• DNA is cut into smaller fragments.

• Loading dye is used to indicate the fragments of DNA are behind the dye • The negative DNA molecule is attracted to the positive electrode. •The smallest fragments move the greatest distance.

 Remove comb and observe wells.  Place carbon paper in each end of the tray.

 Cover with buffer, making sure the allow buffer to

overflow into each end of the tray.  Load gels.  Connect the electrodes.  Turn on power supply.  Allow gels to run – make sure you see bubbles coming from the electrodes.

 It will take about 30 minutes for the gel to

run.  Turn off power supply and remove electrodes.  Pour off buffer into the designated container.  Carefully remove gel from gel box and place in glad container and cover with stain.  Store in appropriate location.

What is significant about the bubbles?
 They indicate that electrolysis of water is

taking place.  One electrode will have a lot of bubbles and the other will have a lesser amount. Why the difference?  The formula for water is H2O and the splitting of the molecule will produce twice as many atoms of hydrogen.

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