Red top tube description.

Red top tube description.

• A. Additive none; Centrifuge after clot; Sample- serum; Test- Chemistry.
• B. Additive- Serum separator; Centrifuge after clot; Sample- Serum; Test- Chemistry.
• C. Additive- EDTA; Centrifuge ASAP; Sample- EDTA plasma; Test- ACTH.
• D. Additive- Heparin; Centrifuge after clot; Sample- plasma; Test- Chemistry.

Answer: (A)

Red-top tubes are plain and contain no additive. Blood is drawn and allowed to clot, then the sample is centrifuged to separate the serum, which is the liquid portion used for many chemistry tests. That’s why the description with no additive, centrifuging after clotting, yielding serum, and testing chemistry is the best fit. The other options imply additives or sample types that don’t apply to red-top tubes (a serum separator would involve a gel barrier and clot activator, EDTA or heparin would produce plasma with anticoagulants, and plasma requires different handling).

Red-top tubes are plain and contain no additive. Blood is drawn and allowed to clot, then the sample is centrifuged to separate the serum, which is the liquid portion used for many chemistry tests. That’s why the description with no additive, centrifuging after clotting, yielding serum, and testing chemistry is the best fit.

The other options imply additives or sample types that don’t apply to red-top tubes (a serum separator would involve a gel barrier and clot activator, EDTA or heparin would produce plasma with anticoagulants, and plasma requires different handling).