American Medical Technologist (AMT) Practice Exam 2026 – All-in-One Resource to Guarantee Exam Success!

The laboratory test that requires blood to be collected in a tube containing sodium citrate is specifically for coagulation studies. Sodium citrate acts as an anticoagulant by binding calcium, which is essential for the coagulation process. This allows the sample to be tested for various clotting factors effectively, leading to accurate results in tests such as Prothrombin Time (PT) and Activated Partial Thromboplastin Time (aPTT).

In coagulation studies, the precise measurement of clotting ability is essential for diagnosis and monitoring of bleeding disorders. The use of sodium citrate ensures that the blood sample remains in a liquid state without forming clots, which would otherwise skew the results significantly.

While the Erythrocyte Sedimentation Rate (ESR) is included in some coagulation panels and can be measured alongside it, it does not require sodium citrate; instead, it often uses a different method. The Complete Blood Count (CBC) and Blood Chemistry Panel do not require sodium citrate either. CBC typically uses EDTA as an anticoagulant, and blood chemistry tests usually involve serum that can be obtained from clotted blood. Thus, it's the specific requirement for sodium citrate in coagulation studies that makes this answer correct.