Given below are two statements:
Statement I: The DNA fragments extracted from gel electrophoresis can be used in construction of recombinant DNA.
Statement II: Smaller size DNA fragments are observed near anode while larger fragments are found near the wells in an agarose gel. In the light of the above statements, choose the most appropriate answer from the options given below:
Both statement I and statement II are correct
Both statement I and statement II are incorrect
Statement I is correct but statement II is incorrect
Statement I is incorrect but statement II is correct
Both statement I and statement II are correct
To determine the correctness of the statements, let us analyze them one by one:
Analysis of Statement I:
During recombinant DNA technology, DNA molecules are cut using restriction enzymes, and the resulting fragments are separated using a technique called gel electrophoresis. The separated DNA fragments of interest are cut out from the agarose gel and extracted from the gel piece. This step is known as elution. The purified DNA fragments obtained after elution are then ligated with a cloning vector to construct recombinant DNA. therefore, Statement I is correct.
Analysis of Statement II:
DNA fragments are negatively charged molecules, so they move towards the positive electrode (anode) when placed in an electric field through a matrix. Agarose gel acts as a sieve, meaning that smaller fragments move faster and travel farther through the pores of the gel than larger fragments. As a result, smaller DNA fragments migrate a longer distance and are observed closer to the anode, whereas larger fragments move slower and remain closer to the wells (near the cathode) where they were loaded. Therefore, Statement II is also correct.
Thus, both Statement I and Statement II are correct statements.