PAG 06 - Gel Electrophoresis

Question 1

What is the purpose of gel electrophoresis?

Answer 1

To separate fragments of DNA. It can be used for DNA fingerprinting.

Question 2

How does gel electrophoresis work?

Answer 2

It separates DNA fragments by their length. Due to the negative charge of the phosphate groups in DNA, it is attracted to the positive electrode (anode), and shorter fragments move at faster rates. Hence, the fragments move different distances within a given time.

Question 3

What are controlled variables in this practical?

Answer 3

Voltage applied
Thickness of agarose gel Temperature
Time allowed for DNA to run Restriction enzymes used

Question 4

What are restriction endonucleases?

Answer 4

They are a type of enzyme derived from bacteria that cuts DNA into fragments at specific restriction sites.

Question 5

Outline the procedure of gel electrophoresis.

Answer 5

1. Use restriction enzymes to cut the DNA sample.
2. Load into wells near the cathode of the agarose
   gel, along with buffer.
3. Apply an electric current and allow the fragments
   to separate. Stop the current before the DNA reaches the end of the gel.

Question 6

Other than DNA, which molecules can be tested using electrophoresis?

Answer 6

Protein, RNA.