Which tube is used for measuring alcohol levels while maintaining sample integrity?

The correct answer is the plain red tube, which is specifically designed for collecting serum samples without any additives that might interfere with certain tests. In the context of measuring alcohol levels, it’s crucial to avoid any substances that could affect the integrity of the sample. The plain red tube allows the blood to clot, and then the serum can be separated, providing a clean and accurate measurement of the alcohol concentration in the sample.

The other tubes listed are not suitable for alcohol measurement due to the presence of additives or anticoagulants. The light blue tube contains sodium citrate, which is used for coagulation tests and would not be appropriate for a test that measures alcohol levels. The gray tube has sodium fluoride, which is specifically intended for preserving glucose levels but can alter the concentration of alcohol, leading to inaccurate results. Finally, the lavender tube contains EDTA, an anticoagulant that can also interfere with the accurate measurement of alcohol levels. Using the right tube is essential to ensure that the measurement reflects the true concentration of alcohol in the blood.