What is multiplexing in DNA analysis?

• A. A method to detect more than one DNA marker in a single analysis.
• B. A method to isolate DNA from multiple samples.
• C. A method to amplify a single DNA marker only.
• D. A method to sequence the entire genome.

Answer: (A)

Multiplexing in DNA analysis means testing multiple DNA markers in a single analysis. In forensic genetics this is done with multiplex PCR, where primers for several STR loci are included in one reaction so those loci are amplified simultaneously. The amplified fragments are then distinguished during analysis by size (and often by different fluorescent labels), allowing data from many markers from a single DNA sample in one run. This increases the amount of information obtained, saves time, and reduces sample use and contamination risk. It isn’t about isolating DNA from multiple samples, nor about amplifying only a single marker, nor sequencing the entire genome.