If complete swaps of incorrect reagents occur (e.g., accidentally swapping AST for the ALT reagents), most instruments will flag QC or patient analyses with multiple error alerts, making it impossible to release any results. However, if this flagging does not occur and QC is analyzed after an incorrect reagent is used, QC results are unlikely to pass, and visualizing the QC failures tends to be easy to identify. For subsequent QC analysis, the QC quantitation is usually very low or undetectable.