Biotechnology and Bioinformatics (1+1)

4.1.6. Limitations of PCR

PCR is an extremely sensitive technique but is prone to contamination from extraneous DNA, leading to false positive results. Another potential problem is due to cross-contamination between samples. It is for this reason that sample preparation, running PCR and post-amplification detection must be carried out in separate rooms.

Concentration of Mg is very crucial as low Mg²⁺ leads to low yields (or no yield) and high Mg2+ leads to accumulation of nonspecific products. Non-specific binding of primers and primer-primer dimmer formation are other possible reasons for unexpected results. Reagents and equipments are costly, hence can’t be afforded by small laboratories.