Skip to main content
Back

Southern Blotting quiz

Control buttons has been changed to "navigation" mode.
1/15
  • What is the main purpose of Southern blotting?
    Southern blotting is used to detect specific DNA sequences in a sample using DNA probes.
  • What type of molecule is used as a probe in Southern blotting?
    A single-stranded, radioactively labeled DNA molecule is used as a probe.
  • How are DNA fragments separated before blotting in Southern blotting?
    DNA fragments are separated by size using gel electrophoresis.
  • What is the role of the denaturing buffer in Southern blotting?
    The denaturing buffer increases the pH to denature DNA, converting it to single-stranded DNA.
  • To what material is the DNA transferred after gel electrophoresis in Southern blotting?
    The DNA is transferred to a nitrocellulose filter paper.
  • Why must DNA be single-stranded before hybridization with the probe?
    DNA must be single-stranded so the probe can bind to its complementary sequence.
  • How is the presence of a specific DNA sequence visualized in Southern blotting?
    It is visualized by detecting radioactivity where the radioactive probe has bound to complementary DNA.
  • What does the appearance of a visible band on the nitrocellulose filter indicate?
    A visible band indicates the presence of DNA fragments complementary to the probe, meaning the sequence of interest is present.
  • What is the difference between Southern, Northern, and Western blotting?
    Southern blotting detects DNA, Northern blotting detects RNA, and Western blotting detects proteins.
  • What is the function of the paper towels in the Southern blotting setup?
    Paper towels help absorb the denaturing buffer, drawing it through the gel and filter paper.
  • Why are radioactive probes used in Southern blotting?
    Radioactive probes allow for the visualization of specific DNA sequences due to their radioactivity.
  • What happens to the DNA in the gel after transfer to the nitrocellulose filter paper?
    The DNA is mostly removed from the gel and is now found on the nitrocellulose filter paper.
  • What determines which DNA fragments the probe will bind to?
    The probe will only bind to DNA fragments that are complementary to its sequence.
  • How can you tell which sample contains the sequence of interest after Southern blotting?
    Samples with visible radioactive bands on the filter paper contain the sequence of interest.
  • What is the first step in the Southern blotting process?
    The first step is to fragment the DNA and separate the fragments by size using gel electrophoresis.