Commercially prepared controls come in either assayed or unassayed forms. Assayed controls are tested by multiple methods before sale and come with measuring system-specific values that are meant to be used as target values for the laboratory using the controls. Assayed controls
- are more expensive than unassayed controls.
- are used to evaluate accuracy and precision.
- may only be suitable for specific method systems.
Unassayed controls have no assigned analyte values provided by the manufacturer. The control values for these materials must be determined by the individual laboratory. Unassayed controls
- are less expensive than assayed controls.
- are used to evaluate accuracy and precision.
- are not linked to specific method systems.
Note: although commercially available control materials are screened for hepatitis antigens and HIV antibodies, control materials should still be handled with precautions since they contain biological materials and could contain infectious agents.
