In which tube should hemoglobin A1C be collected?

The hemoglobin A1C test, which measures the average blood glucose levels over the past two to three months for those with diabetes, is ideally collected in an EDTA tube. This is because EDTA (ethylenediaminetetraacetic acid) acts as an anticoagulant that effectively prevents the blood cells from clotting, thereby preserving the integrity of the hemoglobin for accurate measurement.

The stability of the sample is crucial for reliable results, and EDTA is well-suited for this purpose in hematological tests. Other types of tubes, such as those containing sodium citrate or heparin, may not preserve the hemoglobin in a way that is optimal for A1C testing, as they are used for different applications (sodium citrate for coagulation studies and heparin for certain metabolic tests). The serum separator tube, while useful in separating serum from blood cells, is not appropriate for A1C testing because it may not yield the same accuracy in measuring glycosylated hemoglobin levels as an EDTA tube. Hence, using an EDTA tube ensures that the sample remains stable and provides accurate results for the hemoglobin A1C test.