Arrange the following steps in the correct chronological sequence for the isolation of a specific DNA fragment during recombinant DNA technology: I. Visualisation of DNA bands under UV light. II. Digestion of source DNA with restriction endonucleases. III. Elution of the desired DNA fragment. IV. Loading of DNA samples into agarose gel wells. Choose the correct sequence from the options given below:

Step-by-step solution

The correct sequence of steps for isolating a specific DNA fragment is as follows: First, the source DNA is cut into smaller fragments using restriction endonucleases (Statement II). Next, these DNA fragments are separated based on their size using agarose gel electrophoresis, which begins by loading the samples into the wells of the gel (Statement IV). After the fragments have migrated, they are stained with ethidium bromide and visualised under UV light to locate the desired band (Statement I). Finally, the separ