Gel Electrophoresis What is Gel Electrophoresis Gel electrophoresis











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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.

BIOTECHNOLOGY ¨ 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 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.

Procedure ¨ 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.

PROCEDURE (CONTINUED) ¨ 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 H 2 O and the splitting of the molecule will produce twice as many atoms of hydrogen.