Final answer:
Without adding ACD-A to whole blood before spinning it in the ACP centrifuge, there is a risk of clotting.
Step-by-step explanation:
When blood is collected, it contains platelets that play a crucial role in blood clotting. If ACD-A is not added to whole blood before spinning it in the ACP centrifuge, there is a risk that clotting will occur. Platelets release clotting factors that cause proteins to form over wounds and create a clot. Without ACD-A, the absence of anticoagulant may lead to the activation of platelets and the formation of a clot in the blood sample.