Often, a laboratory using an instrument manufacturer or in-kit control may receive a different control lot with each new reagent lot. This does not provide the laboratory with the benefits of long-term QC monitoring. Independent controls with a longer shelf life allow use of the same control lot over multiple batches of reagents and calibrators, giving the laboratory the ability to detect shifts that may occur with new lot of reagents or calibrators.
A control with a long shelf life allows for long-term QC monitoring across different reagent lots and saves time and money due to fewer lot crossovers. See chart to help provide further explanation.