Platelet (PLT) transfusions play an important role in patients with thrombocytopenia or severely impaired platelet function. Platelet concentrates are prepared from whole-blood donations or by plateletpheresis. In recent years, different instruments have been developed to perform plateletpheresis. We evaluated an apheresis instrument, the Haemonetics MCS (R) + with regard to PLT yield, collection efficiency (CE), and collection rate (CR) in a retrospective, randomized study in 526 donors. In this system, we used leukoreduction filters post collection to obtain leukoreduced products. The Haemonetics MCS (R) + cell separator efficiently collected apheresis platelets with median PLT yields of 3.7 x 10(11), mean CE of 66.69 +/- 13.73% and mean CR of 0.063 +/- 0.013 x 10(11)/min. The median blood volume processed was 3290 (2420-4370) ml, and the median volume of acid citrate dextrose-A (ACD-A) used in collections on the device was 385 (196-517) ml. Also, this device allowed the collection of white blood cell (WBC) reduced plateletpheresis with mean 0.07 +/- 0.15 x 10(6) WBC content. No serious donor or recipient reactions occurred. (C) 2015 Elsevier Ltd. All rights reserved.