Final answer:
The color tube stopper used to collect a glucose test is gray. It prevents clotting and helps preserve the accuracy of the test.
Step-by-step explanation:
The color tube stopper used to collect a glucose test is gray.
The gray stopper indicates that the tube contains an additive that prevents blood from clotting. This is important because clotting can interfere with the accuracy of the glucose test results. The gray stopper is commonly used for tests that require plasma or serum samples, such as glucose tests.
For example, when blood is collected using a gray stopper tube, the blood will be allowed to separate into the plasma or serum layer, which can then be used for the glucose test. The gray stopper also helps to preserve the integrity of the sample as the blood is collected and transported to the laboratory for analysis.