What is the difference between immunoassay screening panels and targeted confirmatory panels?

What is the difference between immunoassay screening panels and targeted confirmatory panels?

• A. Screens test a single drug with follow-up broad screening.
• B. Screens cover multiple drugs broadly; confirmatory panels target specific compounds with high specificity and precise quantification.
• C. Screens test for all substances; confirmatory test none.
• D. Screens provide qualitative results; confirmatory provide qualitative results only.

Answer: (B)

Immunoassay screening panels are built to survey a broad range of drugs in one run, using antibody-based tests that can quickly flag the presence of multiple substances. Because these tests rely on cross-reactivity and are designed for high-throughput, their results are typically qualitative or semi-quantitative—indicating a positive or negative screen and sometimes a rough estimate, not exact amounts. The idea is to cast a wide net first and then move positives to a more precise check. Targeted confirmatory panels, by contrast, use highly specific analytical methods—like GC-MS or LC-MS/MS—to identify and quantify exact compounds with high confidence. They focus on predefined targets and provide precise concentration values, confirming exactly which substances are present. So, screening covers multiple drugs broadly, while confirmatory panels target specific compounds with high specificity and precise quantification.

Immunoassay screening panels are built to survey a broad range of drugs in one run, using antibody-based tests that can quickly flag the presence of multiple substances. Because these tests rely on cross-reactivity and are designed for high-throughput, their results are typically qualitative or semi-quantitative—indicating a positive or negative screen and sometimes a rough estimate, not exact amounts. The idea is to cast a wide net first and then move positives to a more precise check.

Targeted confirmatory panels, by contrast, use highly specific analytical methods—like GC-MS or LC-MS/MS—to identify and quantify exact compounds with high confidence. They focus on predefined targets and provide precise concentration values, confirming exactly which substances are present.

So, screening covers multiple drugs broadly, while confirmatory panels target specific compounds with high specificity and precise quantification.