Which color top is typically used for EDTA to preserve blood cells for hematology?

Which color top is typically used for EDTA to preserve blood cells for hematology?

• A. Gray
• B. Gold
• C. Lavender
• D. Green

Answer: (C)

EDTA is used to preserve blood cells for hematology because it binds calcium and prevents coagulation without disturbing cell morphology. This keeps the cells intact for accurate counting and differentiation. The lavender (purple) top tube contains EDTA and is the standard for CBCs and other hematology tests. Other tube colors serve different purposes: gray tops are fluoride-oxalate for glucose testing, gold tops are clot activator tubes for serum chemistry, and green tops contain heparin for plasma chemistry. Heparin or serum tubes can alter cell appearance, making them less ideal for routine hematology, so EDTA in the lavender-top tube is preferred.

EDTA is used to preserve blood cells for hematology because it binds calcium and prevents coagulation without disturbing cell morphology. This keeps the cells intact for accurate counting and differentiation. The lavender (purple) top tube contains EDTA and is the standard for CBCs and other hematology tests. Other tube colors serve different purposes: gray tops are fluoride-oxalate for glucose testing, gold tops are clot activator tubes for serum chemistry, and green tops contain heparin for plasma chemistry. Heparin or serum tubes can alter cell appearance, making them less ideal for routine hematology, so EDTA in the lavender-top tube is preferred.