Gel Electrophoresis and Foodborne Outbreak Investigation Quiz

What is the primary purpose of gel electrophoresis in forensic science?

• To create DNA samples

• To identify the source of a DNA sample

• To destroy DNA evidence

• To enhance DNA visibility

In gel electrophoresis, why does DNA move towards the positive electrode?

• DNA is neutral

• DNA is positively charged

• DNA is negatively charged

• DNA is magnetic

What is the role of PCR in gel electrophoresis?

• To change the charge of DNA

• To create a single copy of DNA

• To destroy DNA samples

• To amplify specific DNA fragments

How do different DNA fragment lengths affect their movement in gel electrophoresis?

• Longer fragments move faster

• Shorter fragments move slower

• Longer fragments move slower

• All fragments move at the same speed

What is the purpose of the mini Wan DNA marker in the gel electrophoresis lab?

• To provide known fragment lengths for comparison

• To amplify DNA samples

• To identify unknown DNA sequences

• To change the charge of DNA

Why is a positive control used in gel electrophoresis?

• To ensure PCR is functioning correctly

• To contaminate the samples

• To destroy DNA samples

• To change the DNA sequence

What should be observed in the negative control lane if the experiment is uncontaminated?

• A single band

• Multiple bands

• No bands

• A bright band

What is the first step in setting up the gel electrophoresis machine?

• Insert the gel tank

• Load DNA samples

• Pour the buffer solution

• Turn on the blue light

Why is it important to ensure no air is trapped under the gel during setup?

• To prevent DNA degradation

• To ensure even DNA migration

• To enhance DNA visibility

• To change the DNA charge

What conclusion can be drawn if the DNA sample from a bean dip layer matches both the Shigella reference standard and the positive control?

• The layer is contaminated

• The layer is responsible for the outbreak

• The layer contains a different bacterium

• The layer is not responsible for the outbreak