Published online 27 November 2005
Methods Online |
Enhancing the efficiency of a PCR using gold nanoparticles
Department of Engineering Science, National Cheng Kung University Tainan, Taiwan, Republic of China 1Department of Microbiology and Immunology, National Cheng Kung University Tainan, Taiwan, Republic of China
*To whom correspondence should be addressed. Tel: +886 6 276 2395; Fax: +886 6 276 2329; Email: yuclin{at}mail.ncku.edu.tw
Received July 21, 2005. Revised October 14, 2005. Accepted November 10, 2005.
We found that the PCR could be dramatically enhanced by Au nanoparticles. With the addition of 0.7 nM of 13 nm Au nanoparticles into the PCR reagent, the PCR efficiency was increased. Especially when maintaining the same or higher amplification yields, the reaction time could be shortened, and the heating/cooling rates could be increased. The excellent heat transfer property of the nanoparticles should be the major factor in improving the PCR efficiency. Different PCR systems, DNA polymerases, DNA sizes and complex samples were compared in this study. Our results demonstrated that Au nanoparticles increase the sensitivity of PCR detection 5- to 10-fold in a slower PCR system (i.e. conventional PCR) and at least 104-fold in a quicker PCR system (i.e. real-time PCR). After the PCR time was shortened by half, the 100 copies/µl DNA were detectable in real-time PCR with gold colloid added, however, at least 106 copies/µl of DNA were needed to reach a detectable signal level using the PCR reagent without gold colloid. This innovation could improve the PCR efficiency using non-expensive polymerases, and general PCR reagent. It is a new viewpoint in PCR, that nanoparticles can be used to enhance PCR efficiency and shorten reaction times.