Worksheet 5
Protein Electrophoresis
25 points
Name:
Lab Time:
Date Turned in:
Introduction:
1. (3 pts) The agarose gel used in this lab was at a concentration of 5.3% (SDS
agarose in buffer). If we used a 7% gel, the pores would be smaller. Do you think
that would that affect the migration of the proteins? Explain why or why not.
2. (2 pts) View the gel on the last page. Place a mark in the appropriate column.
YES
NO
a. all proteins at #1 (reading across) must be the same protein
b. all proteins at #3 (reading across) must be the same weight
c. all proteins at #7 (reading across) must be the same charge
d. all proteins at #9 (reading across) must have the same
migration distance
Materials and Methods:
3. (2 pts) Why did we use proteins of known size in this lab?
4. (2 pts) The gel on the last page does not show the tracking dye. Draw where it
would be and what it would look like if we had added it to Sample F. Think
carefully about your answer!
5. (2 pts) Research the directions for making percent (w/v) solutions. Assuming
you had access to SDS agarose and gel buffer, how would you have made up the 15
ml of 5.3% gel you used in this lab?
Results:
5. (2 pts) Attach a picture of your agarose gel. In the space below, write a properly
formatted figure legend.
6. (5 points). Using Prism, construct a standard curve with a linear regression line
using the known protein sizes and migration distances from your gel. Properly
format the graph and include a figure legend. Include the slope and y-intercept on
your graph.
Provide the data requested from your group.
a. Migration distances for all bands in lane _________
b. Slope of the line:
(get from instructor):
y-intercept:
Discussion:
8. (3 pts). Calculated size of the LARGEST protein in lane _________
instructor). Use correct units!.
log10 answer=
(get from
non-log10 answer =
9. (2 pts) Transformin is a protein of 25, 200 daltons. Use the data below and the
formula y=mx+b to calculate how far it should migrate on a gel. Hint: you will
need to transform the molecular weight to log10.
m = -30.42
b = 155.9
expected migration distance =
mm
10. (2 pts) Analyze your gel. Are any of the samples on your gel from closely
related individuals? Provide evidence for your answer.
Wells