What is the initial screening procedure used in drug testing?

What is the initial screening procedure used in drug testing?

• A. Gas chromatography
• B. Mass spectrometry
• C. Enzyme/fluoroimmunoassay
• D. Visual inspection

Answer: (C)

In drug testing, the first step is to quickly screen many samples for possible positives, and enzyme/fluoroimmunoassay fits that role perfectly. These immunoassays use antibodies that recognize drug classes or metabolites in urine or other specimens and produce a rapid readout—usually positive or negative—based on predefined cutoffs. They’re fast, cost-effective, and easily automated, making them ideal for high-throughput screening of large sample volumes. If a screen comes back positive, the result isn’t treated as a definitive identification. Instead, it triggers a confirmatory test using more specific instrumentation, typically GC-MS or LC-MS/MS, which can precisely identify and quantify the drug to rule out false positives. Gas chromatography and mass spectrometry, while highly specific and sensitive, are more time-consuming and resource-intensive, so they’re commonly used for confirmation rather than the initial screen. Visual inspection wouldn’t provide reliable or quantifiable drug detection, so it isn’t used as a screening method.

In drug testing, the first step is to quickly screen many samples for possible positives, and enzyme/fluoroimmunoassay fits that role perfectly. These immunoassays use antibodies that recognize drug classes or metabolites in urine or other specimens and produce a rapid readout—usually positive or negative—based on predefined cutoffs. They’re fast, cost-effective, and easily automated, making them ideal for high-throughput screening of large sample volumes.

If a screen comes back positive, the result isn’t treated as a definitive identification. Instead, it triggers a confirmatory test using more specific instrumentation, typically GC-MS or LC-MS/MS, which can precisely identify and quantify the drug to rule out false positives.

Gas chromatography and mass spectrometry, while highly specific and sensitive, are more time-consuming and resource-intensive, so they’re commonly used for confirmation rather than the initial screen. Visual inspection wouldn’t provide reliable or quantifiable drug detection, so it isn’t used as a screening method.