What is the CLSI capillary order of draw?

What is the CLSI capillary order of draw?

• A. EHAS
• B. HEAS
• C. SAHE
• D. AEHS

Answer: (A)

The main idea is understanding why CLSI specifies a capillary draw sequence to minimize additive carryover and protect test integrity. The recommended order is EDTA first, followed by heparin, then ACD, and finally serum. Drawing EDTA first preserves the cellular components needed for CBC and prevents earlier contamination from affecting downstream tests. Next, collecting heparin provides plasma for chemistry without introducing calcium-chelating effects from EDTA into those samples. ACD is used for specialized tests that require preserved leukocytes or other components, so it’s drawn before serum to avoid cross-contamination. Finally, serum is collected last because it relies on clotting; having no anticoagulant in that tube ensures the serum sample isn’t compromised by additives from prior tubes. This sequence helps ensure each test gets the appropriate specimen with minimal interference.

The main idea is understanding why CLSI specifies a capillary draw sequence to minimize additive carryover and protect test integrity. The recommended order is EDTA first, followed by heparin, then ACD, and finally serum. Drawing EDTA first preserves the cellular components needed for CBC and prevents earlier contamination from affecting downstream tests. Next, collecting heparin provides plasma for chemistry without introducing calcium-chelating effects from EDTA into those samples. ACD is used for specialized tests that require preserved leukocytes or other components, so it’s drawn before serum to avoid cross-contamination. Finally, serum is collected last because it relies on clotting; having no anticoagulant in that tube ensures the serum sample isn’t compromised by additives from prior tubes. This sequence helps ensure each test gets the appropriate specimen with minimal interference.