Which tube color, if filled with blood, should not be placed on a rocker?

Which tube color, if filled with blood, should not be placed on a rocker?

• A. Red top
• B. Blue top
• C. Green top
• D. Purple top

Answer: (A)

The main idea is how clotting and additive presence determine how you should handle a blood sample. A red-top tube has no anticoagulant, so the blood is allowed to clot to produce serum. If you place this tube on a rocker, the movement can interfere with proper clot formation and may affect the serum yield and test results. In contrast, tubes that do contain anticoagulants (like blue, green, or purple tops) are designed to be mixed gently to distribute the additive and prevent clotting, so they’re not the target for rocking avoidance in this context. Therefore, the red-top tube should not be rocked.

The main idea is how clotting and additive presence determine how you should handle a blood sample. A red-top tube has no anticoagulant, so the blood is allowed to clot to produce serum. If you place this tube on a rocker, the movement can interfere with proper clot formation and may affect the serum yield and test results. In contrast, tubes that do contain anticoagulants (like blue, green, or purple tops) are designed to be mixed gently to distribute the additive and prevent clotting, so they’re not the target for rocking avoidance in this context. Therefore, the red-top tube should not be rocked.