Which Objective Would Be Best to Use a Southern Blot

Question

Which objective would be best to use a Southern blot rather than a Northern blot?
A) Determine if a gene is present in a genome.
B) Discover gene function.
C) Identify regulatory gene-protein interactions.
D) Quantify expression profiles of a gene.

Accepted Answer

A Southern blot is used to detect the presence or absence of a specific DNA sequence in a sample. This technique is commonly used to identify the presence or absence of a particular gene in a genome, making it the best choice for objective A. A Northern blot is used to detect the presence and quantity of RNA transcripts in a sample, making it more suitable for objective D. Regulatory gene-protein interactions are typically studied using techniques such as chromatin immunoprecipitation (ChIP) or electrophoretic mobility shift assays (EMSA), making objective C more suitable for these techniques. Objective B could potentially use both Southern and Northern blot techniques, depending on the gene of interest and the specific question being asked.