Final answer:
Skin punctures require different color tubes for different tests: purple or lavender for WBC, red for RBC, and green or gray for glucose and electrolyte tests.
Step-by-step explanation:
When doing a skin puncture, the color tubes used for WBC, RBC, glucose, and electrolyte tests depend on the specific test being performed.
For WBC (white blood cell) tests, a purple or lavender-colored tube is generally used. This is because the purple top tube contains an additive called EDTA, which helps prevent clotting of the blood and maintains the integrity of the white blood cells.
For RBC (red blood cell) tests, a red top tube is typically used. The red top tube does not contain any additives and allows for the collection of blood samples without any anticoagulant substances.
For glucose and electrolyte tests, green or gray-colored tubes may be used. These tubes contain different types of additives that help preserve the stability of glucose and electrolytes in the blood sample.