What color tube is used for an ESR test sent to Hematology?

The lavender tube is used for an ESR (Erythrocyte Sedimentation Rate) test because it contains EDTA, an anticoagulant that binds calcium and prevents blood from clotting. This is essential for tests that require whole blood or plasma, as it ensures that the cells remain suspended in the plasma for accurate measurement. The ESR test specifically measures how quickly red blood cells settle at the bottom of a test tube, which can indicate inflammation or other medical conditions. Using the lavender tube guarantees that the sample remains viable for these necessary assessments.

In contrast, the other tube colors mentioned do not contain the appropriate additive for an ESR test. For instance, the pink tube is typically used for blood banking and crossmatching, the gray tube usually contains additives like sodium fluoride for glucose testing, and the orange tube is often used for serum tests. Thus, using the lavender tube is essential for ensuring that the diagnostic requirements of an ESR test are met.