QC Samples The end-product of most analytical laboratories is data. It is therefore imperative that the quality of the data produced meet or exceed performance criteria. The implementation of Quality Control (QC) processes helps control error and estimate uncertainty. QC can be a tool in method development, regulatory processes, laboratory training, and performance monitoring. QC samples can help an analytical laboratory determine its precision, accuracy, linear range, and method ruggedness. QC samples allow the laboratories to fulfill documentation requirements as well as correct errors in root case analysis of a possible failure. Finally, QC samples monitor the effectiveness of the laboratory analysts to produce accurate data.