Gel electrophoresis

Question 1

What is gel electrophoresis?

Answer 1

This is a method of separating DNA fragments according to their size. The fragments may have
been produced by PCR, or by restriction enzymes to cut up larger pieces of DNA
into smaller fragments.

Question 2

Whats the gel made from?

Answer 2

Agarose

Question 3

Method?

Answer 3

• The gel is made from agarose which contains pores in the matrix.
• Once loaded in the gel the DNA is attracted to the positive electrode due to its negative
  charge in the phosphate group.
• The use of fluorescent tags or radioactive markers enables the DNA on the gel to be seen.
• A DNA marker with fragments of known length is run through the gel at the same time as the
  samples.
• By comparing the bands of the samples with the marker the length of the fragments in the
  sample can be worked out.