In which tube should hemoglobin A1C be collected?

Hemoglobin A1C testing requires the use of an EDTA tube because EDTA is an anticoagulant that preserves blood cells and their contents, making it suitable for evaluating the levels of hemoglobin A1C. This test measures the average blood glucose concentration over the past two to three months by assessing the percentage of glucose attached to hemoglobin in red blood cells.

Using an EDTA tube is crucial because it prevents the blood from clotting, allowing for accurate measurement of A1C levels. In contrast, other types of tubes, such as those containing sodium citrate or heparin, may not provide the same level of preservation for the cells needed in this analysis. Serum separator tubes, while useful in many serum-based tests, are not ideal for hemoglobin A1C since the separation of serum could lead to the degradation of the measurement due to the processes involved in serum preparation.