Part 1: Gel Electrophoresis

Part 1: Gel Electrophoresis
Complete both exercises below and submit your answers to the Carmen Quiz. You may work with others
in the class, but each student needs to submit their answers individually.
Agarose gel electrophoresis is a technique used to separate DNA fragments by size. Agarose is a
seaweed-derived gelling agent that creates a semi-permeable matrix, which allows shorter fragments to travel
faster than longer fragments. With the use of a standard called a DNA ladder (Lane 1), we can interpret gels
to determine the size and quantitiy of DNA fragments.
Course Engagement Activity: Biotechnology
1. Which DNA fragment (A, B, C, D, E, or F) is the largest?
2. Which two DNA fragments are the same size?
3. Which lane of the gel has a DNA fragment that is about
700 base pairs?
4. Which DNA fragment (B, C, D, or E) is about the same size
as the lengths of fragment A and fragment F added together?
Actual gels don’t have convenient labels. On the gel to the right,
the labels have been removed but the ladder is the same as in
the previous example.
5. On the gel to the right, write the approximate size of
each DNA fragment.
6. You take the DNA fragment that is in Lane 2 of this gel
and use a restriction enzyme to cut it into two pieces.
Which lane (3, 4, or 5) could be the same sample from
Lane 2 after it was cut into two pieces?
A
B
C
D
E
F
G
Part 2: DNA Fingerprinting
Analyze the following gel samples and get to the bottom of each of these cases! Submit your answers to
the Carmen Quiz.
7. (Right) Lt. Russ is investigating a murder scene. The felon was scratched by
his victim & some of his skin cells were found under the victim’s fingernails. To
which of the suspects do the skin cells belong?
8. (Left) Mr. & Mrs. Jones just gave birth to fraternal
twins. Unfortunately, the nurse has confused the twins
with other babies. The doctors took samples of DNA
from each of the babies and Mr. & Mrs. Jones. Which
two children belong to Mr. & Mrs. Jones?
9. (Left) Mrs. Smith has a baby named Tyra. She believes one of two men can
be the father of her child. A paternity test is done and the results are shown
here. Which of the 2 men is baby Tyra’s father?
10. (Right) Mr. Megabucks, the wealthiest man in the
world, recently died. Three women have since come
forward, claiming to have a child by Megabucks and
demanding a substantial share of his estate. Fortunately, Megabucks anticipated trouble like this before
he died, and he arranged to have a sample of his
blood frozen for DNA typing. Determine which child is
the heir of Mr. Megabucks.Part 1: Gel Electrophoresis
Complete both exercises below and submit your answers to the Carmen Quiz. You may work with others
in the class, but each student needs to submit their answers individually.
Agarose gel electrophoresis is a technique used to separate DNA fragments by size. Agarose is a
seaweed-derived gelling agent that creates a semi-permeable matrix, which allows shorter fragments to travel
faster than longer fragments. With the use of a standard called a DNA ladder (Lane 1), we can interpret gels
to determine the size and quantitiy of DNA fragments.
Course Engagement Activity: Biotechnology
1. Which DNA fragment (A, B, C, D, E, or F) is the largest?
2. Which two DNA fragments are the same size?
3. Which lane of the gel has a DNA fragment that is about
700 base pairs?
4. Which DNA fragment (B, C, D, or E) is about the same size
as the lengths of fragment A and fragment F added together?
Actual gels don’t have convenient labels. On the gel to the right,
the labels have been removed but the ladder is the same as in
the previous example.
5. On the gel to the right, write the approximate size of
each DNA fragment.
6. You take the DNA fragment that is in Lane 2 of this gel
and use a restriction enzyme to cut it into two pieces.
Which lane (3, 4, or 5) could be the same sample from
Lane 2 after it was cut into two pieces?
A
B
C
D
E
F
G
Part 2: DNA Fingerprinting
Analyze the following gel samples and get to the bottom of each of these cases! Submit your answers to
the Carmen Quiz.
7. (Right) Lt. Russ is investigating a murder scene. The felon was scratched by
his victim & some of his skin cells were found under the victim’s fingernails. To
which of the suspects do the skin cells belong?
8. (Left) Mr. & Mrs. Jones just gave birth to fraternal
twins. Unfortunately, the nurse has confused the twins
with other babies. The doctors took samples of DNA
from each of the babies and Mr. & Mrs. Jones. Which
two children belong to Mr. & Mrs. Jones?
9. (Left) Mrs. Smith has a baby named Tyra. She believes one of two men can
be the father of her child. A paternity test is done and the results are shown
here. Which of the 2 men is baby Tyra’s father?
10. (Right) Mr. Megabucks, the wealthiest man in the
world, recently died. Three women have since come
forward, claiming to have a child by Megabucks and
demanding a substantial share of his estate. Fortunately, Megabucks anticipated trouble like this before
he died, and he arranged to have a sample of his
blood frozen for DNA typing. Determine which child is
the heir of Mr. Megabucks.