A diagnostic system performs a first nucleic acid amplification reaction and a second, different nucleic acid amplification reaction. The diagnostic system includes a compartment configured to store at least a first bulk reagent container comprising a first bulk reagent for performing a sample preparation process, and a second bulk reagent container comprising a second bulk reagent for performing the first reaction. The system including a compartment configured to store at least one unit-dose pack comprising a plurality of unit-dose reagents for performing the second reaction. The diagnostic system is configured to perform the sample preparation process using the first bulk reagent on each of a plurality of samples provided to the diagnostic system. The system is configured to perform the first reaction using the second bulk reagent on a first sample subset, and perform the second reaction using the plurality of first unit-dose reagents on a second sample subset.