What can be an advantage of a blue-light transilluminator?

Correct answer: It can reduce UV damage

The governing concept is safer visualization of DNA bands after gel electrophoresis. Conventional ultraviolet illumination can damage DNA through UV-induced lesions, which is undesirable when the band will be recovered for cloning, sequencing, or another downstream application. A blue-light transilluminator uses visible blue light and can reduce such photodamage compared with UV exposure, although appropriate fluorescent stains and instrument settings are still required. Therefore option A is correct. Blue light does not convert DNA into protein, does not make an enzyme permanently inactive, and does not dissolve the agarose gel. Its main benefit is improved preservation of recoverable DNA.