Minimum Detectable Amount (MDA)

The smallest amount (activity or mass) of an analyte in a sample that will be detected with a probability, β, of non-detection (Type II error) while accepting a probability, α, of erroneously deciding that a positive (non-zero) quantity of analyte is present in an appropriate blank sample (Type I error). The MDA is computed using the same value of α as used for the Lc. The MDA depends on both α and β. Measurement results are compared to the Lc, not the MDA; the MDA is used to determine whether a program has adequate detection capability. The MDA will be greater than or equal to the Lc.