What is a common error source in PCR assays?

What is a common error source in PCR assays?

• A. Nucleic acid contamination
• B. Low temperature in machine
• C. High salt concentration
• D. Poor primer design

Answer: (A)

PCR is extremely sensitive, so even tiny amounts of nucleic acid that accidentally get into the reaction can be amplified as if they were the target. This makes nucleic acid contamination the most frequent source of error in PCR assays. Contamination can come from carryover of amplified products, DNA on gloves, benches, or instruments, or from contaminated reagents. Because of this sensitivity, negative controls often reveal contamination by showing amplification where no target should be present. To minimize risk, labs keep setup and amplification areas separate, use dedicated reagents and consumables, practice strict pipetting and handling techniques, and employ measures like filter tips and environmental decontamination. The other listed issues can cause problems with amplification or specificity, but they are less likely to generate the kind of false-positive results that contamination causes.

PCR is extremely sensitive, so even tiny amounts of nucleic acid that accidentally get into the reaction can be amplified as if they were the target. This makes nucleic acid contamination the most frequent source of error in PCR assays. Contamination can come from carryover of amplified products, DNA on gloves, benches, or instruments, or from contaminated reagents. Because of this sensitivity, negative controls often reveal contamination by showing amplification where no target should be present. To minimize risk, labs keep setup and amplification areas separate, use dedicated reagents and consumables, practice strict pipetting and handling techniques, and employ measures like filter tips and environmental decontamination. The other listed issues can cause problems with amplification or specificity, but they are less likely to generate the kind of false-positive results that contamination causes.