Quantum dots induce hot-start effects for Taq-based polymerase chain reaction

Fuming Sang,Xiaolei Ju,Hongyuan Wang,Zhizhou Zhang,Yang Yang

doi:10.4236/jbise.2012.56038

Fuming Sang, Xiaolei Ju + Show 3 more

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https://doi.org/10.4236/jbise.2012.56038

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Abstract

Decent hot-start effects were here reported in Taq DNA polymerase-based polymerase chain reaction (PCR) when water-soluble CdTe quantum dots (QDs) were employed. The hot-start effects were revealed by the higher amplicon yields and distinguished suppression of nonspecific amplification after pre-incubation of PCR mix with quantum dots between 30°C and 56°C. DNA targets were well amplified even after PCR mixture was pre-incubated 3 hr at 30°C or 1 hr at 50°C. Importantly, the effects of QDs nanoparticles could be reversed by increasing the polymerase concentration, suggesting that there was an interaction between QDs and Taq DNA polymerase. Moreover, control experiment indicated that hot-start effect is not primarily due to the reduced polymerase concentration resulted from the above interaction. This study provided another good start to investigate potential implications of quantum dots in key molecular biology techniques.

Highlights

Polymerase chain reaction (PCR), a powerful DNA amplification technique, has been widely used in biological and medical sciences for many years
The effects of quantum dots (QDs) nanoparticles could be reversed by increasing the polymerase concentration, suggesting that there was an interaction between QDs and Taq DNA polymerase
When QDs concentration was high to 0.5 M, no polymerase chain reaction (PCR) products were attained, which suggested that hot start PCR was inhibited obviously when excessive QDs were added

Summary

Introduction

Polymerase chain reaction (PCR), a powerful DNA amplification technique, has been widely used in biological and medical sciences for many years. PCR technology has not reached its summit because it is still frequently impaired by low specificity and sensitivity arising from the non-specific amplification products, such as primer dimers and mispriming products. Hot start PCR (HS PCR) is one important technique to prevent those unwanted non-specific PCR products. The first one is to withdraw one key component (e.g., dNTP or DNA polymerase) and introduce it once the desired temperature is reached through the manual addition or a temporary barrier [1,2,3,4]. The third approach achieves HS effects by the modifications of the primers or dNTP [9,10,11]

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