CLSI (C24-A3, Section 6.2) suggests the following considerations when selecting control materials:
The control material should share common characteristics with the intended patient sample types.
To minimize the amount of testing required when a lot change occurs the laboratory should purchase a large enough volume of control materials. If practical, at least a one year supply is recommended.
Upon opening, the control material should demonstrate stability over the claimed shelf life.
The vial to vial variance should be much less than the expected variance of the procedure being tested.
To verify proper performance over the measuring range, the control material should consist of a sufficient number of levels and concentrations.
Note: Local government regulations might specify a minimum number of control levels for particular testing protocols.
The control material should contain the analyte to be tested in concentrations at the clinically relevant levels that might be seen in patient samples.
