NPS Phlebotomy Practice Exam

Color-coded stopper tubes convey the additive inside and guide how the specimen will be used. Lavender-topped tubes contain EDTA and are commonly used for hematology tests like the CBC. In many practices, lavender tubes are being replaced with pink-stopper tubes to standardize EDTA specimens across departments and to make blood-bank workflow more distinct. Pink tops still use EDTA, so the way the blood is preserved and the test results you get from EDTA tubes are the same; the change is about labeling and workflow safety rather than the chemical effect. The pink color helps differentiate EDTA specimens in blood-bank-related processing, reducing mix-ups and speeding up processing. Other common colors indicate different additives (for example blue for citrate, green for heparin, red for serum/no additive), which explains why pink replaces lavender only when the goal is to keep EDTA usage clear within a blood-bank context.