Which color top is used for citrate anticoagulant testing in coagulation studies?

Which color top is used for citrate anticoagulant testing in coagulation studies?

• A. Red
• B. Light Blue
• C. Yellow
• D. Lavender

Answer: (B)

Light blue-top tubes contain sodium citrate, which acts as the anticoagulant for coagulation testing. Citrate binds calcium in the blood, preventing clotting so clotting times like PT and aPTT can be measured. The tube must be filled to the correct volume to maintain the proper 9:1 blood-to-anticoagulant ratio; otherwise, results can be skewed. After collection, calcium is added back during the assay to allow clot formation for measurement. Other colors correspond to different additives and uses: red-top for serum tests, lavender-top for EDTA (hematology), green-top for heparin, and yellow-top for acid-citrate-dextrose (ACD) used in specialized tests like donor studies or DNA work.

Light blue-top tubes contain sodium citrate, which acts as the anticoagulant for coagulation testing. Citrate binds calcium in the blood, preventing clotting so clotting times like PT and aPTT can be measured. The tube must be filled to the correct volume to maintain the proper 9:1 blood-to-anticoagulant ratio; otherwise, results can be skewed. After collection, calcium is added back during the assay to allow clot formation for measurement. Other colors correspond to different additives and uses: red-top for serum tests, lavender-top for EDTA (hematology), green-top for heparin, and yellow-top for acid-citrate-dextrose (ACD) used in specialized tests like donor studies or DNA work.