We have had issues for several weeks with our WB cor QC #2 tube failing QC randomly. It doesn't do it every day, but each time, we see what looks like "trash" in the anti A well of the CMT strip while doing the blood type. (The blood type should be B neg). We have tried spinning the QC for 3 minutes instead of 5, per suggestion of Immucor. We've also tried spinning the QC tubes with the caps off (as was recommended by Immucor when the threads for the tube caps were on the inside of the tubes and little flecks of dried blood were getting in the tube, causing false positive reactions), and reaming the tubes with wooden sticks, and those things seem to help sometimes, but not always. Our affiliate hospital is having the same issues and I was wondering how many more people out there are having these issues as well, and if you are, any suggestions you have woule be appreciated. This issue is very frustrating, as it wastes time, reagent, money, etc. It has occurred with several different lots of QC, reagents. Please help!!!