What specimens require protection from light?

The correct response highlights the necessity for certain specimens to be shielded from light to ensure the accuracy of laboratory results. Specifically, bilirubin, vitamin B12, and carotene are photosensitive compounds; they can degrade or undergo changes when exposed to light, leading to falsely lowered measurements at the time of analysis.

Bilirubin, for instance, is particularly sensitive and can break down when exposed to light, causing erroneous results in diagnostic tests related to liver function and jaundice detection. Vitamin B12 and carotene also require similar precautions to maintain their integrity in laboratory analyses. To prevent any degradation caused by light, specimens containing these substances should be protected by wrapping them in aluminum foil or using amber-colored containers at the time of collection and during transport to the laboratory.

The other options list specimens that do not share this photodegradation concern, thus emphasizing the importance of understanding which compounds are susceptible to light exposure and the correct handling of such specimens for accurate laboratory results.