Gel Electrophoresis

In what ways is Gel Electrophoresis useful?

-Determine sizes of genes. -Look for variation of genes in a population. -Determine relationship between individuals. -Identify unknown samples of DNA. -Sequence DNA samples

How is DNA fingerprinting useful?

-Forensics uses this technique frequently for determination of suspects. -Since the random repeats are genetically inherited, we can use this to determine paternity. -identify unknown remains by comparing them to known DNA samples

How is the gel prepared for this process?

1.Agarose powder is mixed with water and boiled. 2.A comb is inserted into the chamber which will cast the wells. 3.The agarose is poured in and cooled to solidify.

What is Agarose?

A carbohydrate polymer made from seaweed. It forms a gelatin with a complex pattern that can act as a filter for various molecules

How is the DNA loaded into the gel?

A micropipette is used to place the samples of DNA into the 'Wells' and because of the loading dye, the DNA is able to sink down.

How is the DNA prepared for this process?

A restriction enzyme is used to slice the DNA into different sized fragments, due to unique bases. These fragments then are combined with a loading dye to keep them visible and dense.

How does electrophoresis come into play for DNA fingerprinting?

Because the 'junk DNA' is cut into different fragments, we can separate them and see different patterns by using electrophoresis.

Why would it be necessary to run a marker sample at the same time as the actual DNA?

It allows us to compare fragment sizes of the DNA being tested

What is DNA fingerprinting?

It is creating a unique pattern of lines, based on a person's unique sequence of bases from their DNA (not their actual finger print)

What does Gel Electrophoresis basically do to DNA?

It separates the DNA into fragments, where electricity is run through the gel and the negatively charged DNA travels (the larger fragments traveling slower) towards the positive end of the gel.

What is first done to DNA for fingerprinting?

Restriction enzymes cut out this section of junk DNA with the random repeats in it. (the length of the DNA varies due to the variable number of repeats)

How is this process run, after everything has been prepared and loaded?

The chamber is now connected to a power source. The wells are placed near the negative terminal Since the DNA has a negative charge due to the phosphate groups, they are attracted to the positive terminal.

What is 'Junk DNA'?

Useless DNA that isn't coded for any protein, but it is important because everyones 'junk DNA' is unique