A lab technician runs the results of a simple PCR reaction through a gel electrophoresis to test a sample of imported hamburger meat for the presence of a DNA sequence that is known to be found in kangaroos and not in cows. What exactly will he be looking for?
A) A green glow in the PCR reaction mix from GFP
B) A particular sequence of nucleotides, as determined by Sanger sequencing
C) A DNA band of a certain size on a gel
D) A green glow on a gel size on a gel
I think the answer is C) A DNA band of a certain size on a gel
correct
You are correct! The lab technician will be looking for a DNA band of a certain size on a gel.
To explain how the lab technician reaches this conclusion, we need to understand the process of gel electrophoresis in PCR.
Polymerase Chain Reaction (PCR) is a technique used to amplify a specific DNA sequence. In this case, the lab technician is using PCR to amplify a DNA sequence that is known to be found in kangaroos but not in cows.
After the PCR reaction, the lab technician needs to analyze the amplified DNA. Gel electrophoresis is commonly used for this purpose.
Gel electrophoresis involves loading the PCR products onto a gel, typically made of agarose, and subjecting it to an electric field. The DNA molecules migrate through the gel based on their size.
In this particular experiment, the lab technician is searching for a DNA sequence that is unique to kangaroos and not found in cows. The PCR amplification will result in multiple copies of this unique sequence.
By running the PCR product through the gel electrophoresis, the DNA molecules will separate based on their size. Smaller DNA fragments will migrate faster through the gel, while larger fragments will migrate slower.
The technician is looking for a specific DNA band of a certain size on the gel. This DNA band represents the amplified DNA sequence of interest. If the DNA band is present and matches the expected size, it indicates the presence of the kangaroo DNA sequence in the imported hamburger meat.
Therefore, the correct answer is indeed C) A DNA band of a certain size on a gel.