Which sample is drawn first in the order of draw?

In phlebotomy, the order of draw is crucial to prevent contamination of samples and ensure accurate test results. Blood culture samples are drawn first because they are most susceptible to contamination from other tubes. Blood cultures are used to detect infections by identifying bacteria or fungi in the bloodstream. Collecting these samples before others minimizes the risk of cross-contamination and ensures the integrity of the results.

When drawing blood, samples collected afterward—like those in red plastic tubes, light blue tubes, or gold/tiger/marble tubes—can contain additives that may interfere with the culture. Therefore, starting with the blood culture helps maintain the pristine nature of the specimen which is paramount for accurate microbial detection and analysis.