Which sequence best represents the molecular testing workflow?

• A. Extraction, denaturation, annealing, extension, sequencing
• B. Growth in culture, staining, imaging, sequencing
• C. Extraction, quantitation, evaluation, amplification, visualization
• D. Isolation, purification, sequencing

Answer: (C)

When evaluating a molecular testing workflow, the sequence should move from raw sample to a reliable readout with appropriate quality checks along the way. Start by extracting nucleic acids from the specimen to access the target material. Then quantify the extract to confirm there is enough material and to gauge overall concentration. Next, evaluate the extract’s quality to ensure purity and integrity, so inhibitors or degradation won’t distort results. After that, amplify the target nucleic acids to generate a detectable signal, which is often essential when starting material is scarce. Finally, visualize or detect the amplified product to obtain the test result, such as through a readout like a gel or a fluorescence-based measurement. This order—extraction, quantitation, evaluation, amplification, visualization—captures the logical progression of turning a clinical sample into a measurable molecular result. The other options either focus on specific PCR steps without the broader workflow, rely on culture-based methods, or omit key quality checks and amplification, making them less representative of the standard process.