Final answer:
The additive in a light blue top tube is sodium citrate, which is used as an anticoagulant for blood sample tests.
Step-by-step explanation:
The additive in the light blue top tube is sodium citrate. Sodium citrate acts as an anticoagulant by binding calcium ions in the blood, preventing blood clotting, and stabilizing blood samples for analysis. It's commonly used for coagulation tests in medical laboratories.
When handling plasma samples that require anticoagulants, sodium citrate is crucial. For instance, the addition of o-phosphoric acid to plasma samples, which are then loaded onto HLB-96 well cartridges, requires careful preparation of the sample with the correct anticoagulant to ensure reliable results in sensitive detection techniques.