Which substance must be protected from light during specimen collection?

Bilirubin is a substance that must be protected from light during specimen collection because it is photosensitive. Exposure to light can lead to the breakdown of bilirubin into other compounds, which can result in inaccurate laboratory results. It is crucial for healthcare professionals to ensure that samples are either collected in amber tubes or wrapped in aluminum foil immediately after collection to prevent light exposure. This preservation is vital for accurate diagnosis and treatment decisions regarding conditions such as liver disease, hemolytic anemia, and jaundice.

In contrast, hemoglobin, glucose, and cholesterol are not significantly affected by light exposure during specimen collection, making them less critical in terms of light protection.