We are using a Sorvall Cellwasher 2. We do a daily check for fill levels by visual inspection, and weekly measure the dispense volume (as well as daily and weekly cleaning). RPMs, timer checks, and electrical checks are done quarterly by Bio Med. The AABB recommends checking resuspension of the red cell button, dryness of the cell button, and inspection of the size of the cell button after saline is dispensed. There is no recommendation for how often this should be done. Their procedure requires that tubes are placed all 12 slots. Is anyone doing this, and, if so, how often?