Question

You would like to see if the gene that you are studying in mouse has a homolog in humans. To do this you decide to do a Southern blot. You believe the gene sequence will be not be highly conserved. Therefore, you would like to select conditions to hybridize your probe with low stringency to find as many candidates as possible. Which condition (in term of slat concentration) will you use? Select one:

a. At Lower Salt Concentration

b. At Higher Salt Concentration

Answer 1

At Higher Salt Concentration

As their will be difference in gene sequence of the DNA of mouse and humans and to reduce the hybrids formation of these two type of genome sequence high amount of salt is added which will prevent the formation of hybrids of the genome which can give a false result and may increase the stringency to lower such cases and stringency a high amount of salt is added in the southern blotting technique which causes the break down to hybrid genome sequences and lower the stringency