Gel Electrophoresis

Question 1

Gel Electrophoresis

Answer 1

A method of seperating fragments of DNA based on their length (molecular length)

Question 2

steps of gel electrophoresis

Answer 2

1) loading dye added to DNA samples to improve visibility and cause DNA to sink into the well

2) DNA samples loaded into agar wells

3) Agal gel is porus (containing gaps for the DNA to move through)

4) Agar also includes a DNA fluorescence stain which binds to the DNA and allows for it to be seen under UV light

5) Agar is surrounded by buffer solution which increases ability for charge to flow

Question 3

Charge of gel electrophoresis

Answer 3

• The negative electrode is positioned at the top and the positive at the bottom.
• Charge is run through the tank and DNA is attached to the positive electrode (DNA is negatively charged)

Question 4

Movement through agar (fragment size)

Answer 4

• DNA fragments separate according to size
• Smaller Fragments are able to travel further through the porous agar
• Density of the gel, the strength of electric current and amount of time will also impact the distance the fragments travel.

Question 5

DNA Ladder

Answer 5

Contains DNA fragments of known length - used to compare to unknow sample fragments to estimate their fragment length