Biology - HOT Science Lab

Student
DNA Electrophoresis Simulation
(Adapted from: Mike Basham, El Dorado High School)
NGSSS:
SC.912.L.16.10 Evaluate the impact of biotechnology on the individual, society and the
environment, including medical and ethical issues. (AA)
Background Information:
Methods of DNA identification have been applied to many branches of science and technology,
including medicine (prenatal tests, genetic screening), conservation biology (guiding captive
breeding programs for endangered species), and forensic science. One of these techniques
involves gel electrophoresis.
DNA samples are often subjected to gel electrophoresis to characterize the size and number of
different fragments in the sample. Gel electrophoresis is used to analyze DNA or proteins.
Enzymes are used to cut the long DNA or protein samples at specific locations to form the
fragments. Then, the DNA or protein fragments are placed in a "well" with a DNA dye along the
top of the jello-like gel (agarose gel). Next, a current is applied to the gel, and the electrically
charged fragments of the sample migrate through the gel away from the wells. Strongly charged
pieces tend to migrate more quickly and, larger pieces migrate more slowly, since they have
more difficulty slipping through the gel's matrix. Because DNA is a negatively charged molecule,
it will always move toward the positive end of the gel electrophoresis box (red electrode). By
comparing the banding patterns of the samples with known substances (standard), scientists
can learn about the DNA or protein fragments. Repeated experiments with different enzymes
that cut at different locations help scientists determine the makeup of the DNA or protein
sample.
Problem Statement: Will a small fragment of DNA move faster than a larger fragment of DNA
Safety:
Take precautions to avoid injuring yourself or others when the experiment involves
physical activity.
Alert your teacher if there is any reason you should not participate in the activity.
Vocabulary: biotechnology, genetic engineering, gel electrophoresis, DNA fingerprinting, DNA
base pairs, restriction enzyme, genome, genetic marker
Materials:
Football, soccer or other large grass field (It is important to use a grass field in case
students fall during the activity.)
50m or 100m measuring tape
Stopwatch or other timing device
Biology HSL Page 296
Curriculum and Instruction