What is the correct order of draw for blood collection?

The correct order of draw is important in phlebotomy to prevent cross-contamination of additives from one collection tube to another. Option C includes blood cultures as the first step, which is crucial because it helps to ensure that any potential contaminants from the skin are not introduced into samples meant for culture. Following this, the light blue tube is used next, as it contains sodium citrate, which can affect coagulation tests if it is contaminated with additives from other tubes.

After the light blue tube, the red tube is collected, which typically contains no additives and is used for serological tests. The gold or tiger top tube, which contains a gel separator and is used for serum tests, is drawn next. This is followed by the green tube, which contains heparin for plasma tests, and then the lavender tube, which often contains EDTA as an anticoagulant for complete blood counts and other tests. The final draw is the gray tube, which contains additives like sodium fluoride or potassium oxalate for glucose testing, thereby ensuring that any potential interference with glucose levels is minimized.

This careful ordering ensures the integrity of each specimen by maintaining the purity of the samples needed for accurate diagnostics, which is the primary reason option C is the correct order of