Manoj P
a Rajiv Gandhi Centre for Biotechnology , Thycaud P.O. , Thiruvananthapuram , Kerala , India.
Mitochondrial DNA A DNA Mapp Seq Anal. 2016;27(1):742-6. doi: 10.3109/19401736.2014.913168. Epub 2014 Apr 29.
Digital Polymerase Chain Reaction (dPCR) is used to quantify nucleic acids and its applications are in the detection and precise quantification of low-level pathogens, rare genetic sequences, quantification of copy number variants, rare mutations and in relative gene expressions. Here the PCR is performed in large number of reaction chambers or partitions and the reaction is carried out in each partition individually. This separation allows a more reliable collection and sensitive measurement of nucleic acid. Results are calculated by counting amplified target sequence (positive droplets) and the number of partitions in which there is no amplification (negative droplets). The mean number of target sequences was calculated by Poisson Algorithm. Poisson correction compensates the presence of more than one copy of target gene in any droplets. The method provides information with accuracy and precision which is highly reproducible and less susceptible to inhibitors than qPCR. It has been demonstrated in studying variations in gene sequences, such as copy number variants and point mutations, distinguishing differences between expression of nearly identical alleles, assessment of clinically relevant genetic variations and it is routinely used for clonal amplification of samples for NGS methods. dPCR enables more reliable predictors of tumor status and patient prognosis by absolute quantitation using reference normalizations. Rare mitochondrial DNA deletions associated with a range of diseases and disorders as well as aging can be accurately detected with droplet digital PCR.
数字聚合酶链反应(dPCR)用于核酸定量,其应用包括检测和精确定量低水平病原体、罕见基因序列、拷贝数变异定量、罕见突变以及相对基因表达。在此,PCR在大量反应室或分区中进行,每个分区单独进行反应。这种分离使得核酸的收集更可靠、测量更灵敏。通过计数扩增的靶序列(阳性液滴)和无扩增的分区数量(阴性液滴)来计算结果。靶序列的平均数通过泊松算法计算。泊松校正可补偿任何液滴中存在多个靶基因拷贝的情况。该方法提供的信息准确且精确,具有高度可重复性,并且比定量聚合酶链反应(qPCR)更不易受抑制剂影响。它已被用于研究基因序列变异,如拷贝数变异和点突变,区分几乎相同等位基因表达之间的差异,评估临床相关的基因变异,并且常规用于下一代测序(NGS)方法的样本克隆扩增。dPCR通过使用参考归一化进行绝对定量,能够更可靠地预测肿瘤状态和患者预后。通过液滴数字PCR可以准确检测与一系列疾病、病症以及衰老相关的罕见线粒体DNA缺失。