Plateletpheresis is a medical procedure that separates and collects platelets from a person's blood. During the process, blood is drawn from the patient, and a machine called apheresis separates the platelets from other blood components, such as red blood cells and plasma. The remaining blood is then returned to the patient. This procedure is often used to collect platelets for patients who need them due to conditions like leukemia or thrombocytopenia. It can also be performed on healthy donors to help patients undergoing treatments like chemotherapy, where platelet levels may drop significantly.