Name: ___________________________________________ Date: ________________
GEL ELECTROPHORESIS VIRTUAL LAB
Directions: Log on the computer and go to http://learn.genetics.utah.edu/content/labs/gel/
For each section read the question first and then read through the information on the
website. As you go through the virtual lab, be sure to read all directions, follow all
prompts given to you, and answer all of the following questions.
DNA STRAND SIZE
1. How can you sort and measure DNA strands if we can not see or touch them
2. Gel Electrophoresis sorts DNA according to what?
3. What other molecules does electrophoresis come in handy for separating?
4.
How do we make the DNA move?
5. DNA is negatively charged. So we put the wells that will contain the DNA by the
_______________(positive or negative) end of a gel so the charges will repel
causing the DNA to _______________ toward the ________________(positive
or negative) end. (Use the animation to help answer this question)
6. Explain how DNA strands sort themselves when they move through the gel.
7. Which strands move the fastest through the gel?
8. Which strands move the slowest?
9. What is the purpose of staining the gel?
STEP 1: MAKE THE GEL READ ALL OF THE QUESTIONS BEFORE YOU START THIS SECTION
10. What materials are needed to make a gel?
11. What is agarose?
12. What is the purpose of the comb?
STEP 2: SET UP THE GEL APPARATUS READ ALL OF THE QUESTIONS BEFORE YOU START
13. What materials do you need to set up the electrophoresis box?
14. Why do we add buffer to the electrophoresis box?
STEP 3: LOAD THE DNA SAMPLES INTO THE GEL
15. What materials do you need to load the DNA samples into the gel?
16. What does the DNA size standard contain?
17. What does running the size standard give you?
STEP 4: HOOK UP THE ELECTRICAL CURRENT AND RUN THE GEL
18. What do the bubbles on the electrodes tell you?
STEP 5: STAIN THE GEL AND ANALYZE THE RESULTS
19. What is ethidium bromide and what does it do?
20. What is a bp?
21. What are the approximate lengths of the strands in the DNA sample that you ran?
a.
b.
c.
22. How did you determine these approximate lengths of DNA?
23. What units are used to measure DNA strand length?