Good morning- I have always followed the CLIA / CMS / CFR guidelines, which requires us to follow the manufacturer's instructions. When you read the inserts, the reagents we are using clearly state do not use beyond expiration. I don't consider expired panel cells to be acceptable, as many QC for reactivity, but don't test for each antigen trying to include or exclude. It is an old practice, the same as not QCing upon receipt, and noting reactivity of any kind to show acceptable performance. We have not had any additional expense nor identification issues with using in dated reagents in our Transfusion Service. I have trouble not citing folks when I see old outdated panels filling banks on inspections.