Final answer:
Light blue topped tubes in medical settings contain sodium citrate, which is used as an anticoagulant for coagulation testing such as PT, aPTT, and TT.
Step-by-step explanation:
The light blue topped tubes commonly encountered in a medical laboratory are known for holding an anticoagulant called sodium citrate. Sodium citrate prevents blood from clotting, which makes it essential for coagulation testing. These tubes are filled with a blood sample and must be filled to the proper level to ensure the correct ratio of blood to anticoagulant.
This is crucial because an incorrect ratio may lead to inaccurate test results. The most common tests using light blue topped tubes include prothrombin time (PT), activated partial thromboplastin time (aPTT), and thrombin time (TT). When a healthcare professional draws blood into these tubes, it is vital they are handled with care to prevent hemolysis and ensure the integrity of the sample.