1.1.6

Question 1

What is the purpose of gel electrophoresis?

Answer 1

to separate mixtures of DNA, RNA, or proteins according to molecular size.

Question 2

Identify the wells, marker, lanes, positive vs. negative ends, and direction of DNA movement on a gel.

Answer 2

(picture)

Question 3

Which travels farthest on a gel - shorter or longer pieces of DNA?

Answer 3

Shorter pieces of DNA move faster than longer pieces and will move further.

Question 4

Is DNA positively or negatively charged? How does that influence how it travels on a gel?

Answer 4

They are negatively charged so that they will move towards the positively charged side.

Question 5

When micropipetting, what is the first stop used for? And what is the second stop used for?

Answer 5

We use the first stop to dispense liquid while using the second to fully empty the tip.

Question 6

Know how to determine approximate band size using the DNA marker on a gel.

Answer 6

Compare it to the size of the band in the sample DNA ladder.

Question 7

Be able to interpret the results of gel electrophoresis.

Answer 7

a) a thick band signifies a large amount of DNA molecules, while a thin band indicates a smaller quantity.

b) The position of DNA fragments depends on their size: shorter fragments migrate faster and are found near the bottom, while larger fragments move more slowly and remain near the top.

c)Referring to the ladder on the side of the equipment will help determine the number of molecules

Question 8

Be able to identify whose DNA matches the crime scene on a gel.

Answer 8

Gel electrophoresis is used to create DNA fingerprints from crime scene and suspect samples. A match between samples suggests which suspect committed the crime.