When using a butterfly needle, which tube should be drawn before a light blue tube?

When using a butterfly needle for blood collection, the order of draw is crucial to prevent cross-contamination of additives between tubes. The light blue tube contains sodium citrate, an anticoagulant that requires proper blood-to-additive ratios for accurate testing. To maintain the integrity of the sample, it is important to draw any tubes with clot activators or gel barriers before the light blue tube.

The SST (serum separator tube) typically contains a clot activator and is used for serum testing. By drawing the SST first, the blood can clot appropriately before a centrifuge is used, ensuring that the serum can be separated without any contamination that could affect coagulation testing in the light blue tube. This order helps ensure clinically accurate results while adhering to the recommended protocol.

The other tubes mentioned, which may have various additives, can potentially compromise the citrate's anticoagulation properties if drawn before the light blue tube. Therefore, following this order of draw is essential for accurate laboratory results.