Laboratory test tubes serve various functions in research, diagnostics, and education. They are commonly used to contain small volumes of liquid or solid samples during testing and observation. Their compact design and easy visibility make them a practical choice for quick assessments and chemical reactions.

In chemistry labs, test tubes are used for reaction experiments, solution preparation, and heating small volumes over flame. In biology and medical fields, they often store blood, urine, or other biological samples. When paired with a centrifuge, certain types of test tubes are used for separating components based on density.

Handling of test tubes typically involves the use of tube racks, holders, or clamps to maintain safety and organization. Depending on the procedure, test tubes may be labeled for tracking and data management. Some are also designed to be compatible with sealing caps, reducing the risk of contamination or evaporation.

Test tubes are part of a broader range of laboratory consumables that support standardized, repeatable procedures in controlled environments. Their adaptability and availability contribute to their continued use across multiple scientific fields.