Unraveling DNA Evidence Through Gel Electrophoresis

The video tutorial explains how to conduct a DNA comparison experiment using electrophoresis. It begins with preparing DNA samples from a crime scene and suspects, followed by setting up and running an electrophoresis gel. The process involves preparing the gel, setting up the gel bed, and running the electrophoresis to separate DNA fragments. Finally, the video covers how to view and analyze the results using a transilluminator to identify matching DNA patterns.

What is the first step in preparing the DNA samples for comparison?

• Adding ethidium bromide

• Labeling the microtest tubes

• Boiling the agarose solution

• Connecting the electrodes

Why is it important to use a fresh micropipette for each DNA transfer?

• To prevent contamination

• To ensure the gel solidifies

• To speed up the electrophoresis

• To enhance the dye luminescence

What is the purpose of incubating the DNA samples at 37 degrees?

• To view the DNA bands

• To activate the enzymes

• To dissolve the agarose powder

• To solidify the gel

How do smaller DNA molecules behave in an agarose gel compared to larger ones?

• They move in the opposite direction

• They move more slowly

• They move more quickly

• They remain stationary

What is the purpose of adding glycerol to the gel loading solution?

• To make the gel transparent

• To help the sample sink into the well

• To increase the voltage

• To prevent the gel from tearing

What is the role of ethidium bromide in the electrophoresis process?

• To make the DNA bands visible under UV light

• To speed up the electrophoresis

• To make the gel solidify

• To dissolve the DNA

What indicates that the current is flowing properly during electrophoresis?

• The gel becomes clear

• Bubbles form on the electrodes

• The dye changes color

• The gel solidifies

Why is it important to allow the tracking dye to migrate at least 4 centimeters?

• To prevent contamination

• To allow the DNA bands to separate

• To ensure the gel is solidified

• To enhance the dye luminescence

What happens to the dye in the samples when exposed to ultraviolet light?

• It evaporates

• It luminesces

• It solidifies

• It dissolves

How can you determine if two DNA samples come from the same person?

• They have the same pattern of bands

• They move at the same speed in the gel

• They have the same enzyme

• They glow the same under UV light