Next-generation sequencing (NGS) and polymerase chain reaction (PCR) are both techniques used to identify DNA sequences, but there are significant there are differences. The basic differences between these two technologies are explained in simple terms.

PCR (polymerase chain reaction)

PCR is a method of selectively replicating specific DNA regions in large numbers.Short DNA primers are used to identify the DNA region of interest and the DNA polymerase enzyme is used toreplicate the region thousands or tens of thousands of times.This allows even very small amounts of DNA samples to produce analyzable quantities of DNA.PCR is relatively simple and fast and is suitable for detecting the presence of specific genes.

Next generation sequencers (NGS)

Next-generation sequencing is a technique for sequencing many DNA fragments simultaneously at high speed, in contrast to PCR, which amplifies a single DNA region. NGS begins by DNA randomly fragmented into many small pieces and a short DNA sequence called an adaptor is added to each fragment. These fragments are fixed to a surface called a flow cell, where each fragment is sequenced simultaneously and in parallel. In each cycle, nucleotides with fluorescent markers are added and their fluorescence is read by a laser to determine the DNA sequence.

PCR and NGS.

PCR technology is sometimes used in the NGS process; it is common for PCR to be used to amplify specific DNA fragments during the sample preparation phase of NGS. This PCR step ensures that there is sufficient amount of DNA to be sequenced. However, the main strength of NGS lies in its ability to simultaneously process millions to billions of DNA fragments at a time. This enables a wide range of applications, such as whole genome sequencing, profiling of expressed genes and even the analysis of epigenetic changes.

NGS is sometimes compared to ‘high-volume PCR’ because of its high-throughput nature, with millions of sequencing reactions taking place simultaneously. In reality, however, NGS provides more information than PCR, enabling more complex and comprehensive analysis of genetic information.

医師監修監修日：2024年9月1日

岡博史（おかひろし）

医師・医学博士／ヒロクリニック統括院長

YouTubeチャンネルなどを通じて、遺伝子やNIPT（新型出生前診断）についてわかりやすく発信しています。

略歴

1996年慶應義塾大学医学部卒業
2004年慶應義塾大学医学博士号取得
2005年慶應義塾大学皮膚科学教室助手
2008年ヒロ皮フ形成クリニック開業
2009年医療法人社団福美会理事長
2015年医療法人社団福美会理事

資格・所属

CAPラボディレクター
日本皮膚科学会皮膚科専門医
日本医師会産業医
東京衛生検査所指導監督医

発信・関連リンク

この記事は、ヒロクリニックNIPPTの編集・監修体制にもとづき、資格を持つ医師が内容を確認しています。

医師監修監修日：2024年9月1日

堤修一（つつみしゅういち）

医師・医学博士／ヒロクリニック博多駅前院院長

略歴

1993年東京大学医学部医学科卒業
2016〜2019年東京大学先端科学技術研究センター准教授

発信・関連リンク

プロフィール詳細

この記事は、ヒロクリニックNIPPTの編集・監修体制にもとづき、資格を持つ医師が内容を確認しています。

参考文献

Margulies M, Egholm M, Altman WE, Attiya S, Bader JS, Bemben LA, et al. Genome sequencing in microfabricated high-density picolitre reactors. Nature. 2005 Sep 15;437(7057):376-80.
Bentley DR, Balasubramanian S, Swerdlow HP, Smith GP, Milton J, Brown CG, et al. Accurate whole human genome sequencing using reversible terminator chemistry. Nature. 2008 Nov 6;456(7218):53-9.
Metzker ML. Sequencing technologies - the next generation. Nat Rev Genet. 2010 Jan;11(1):31-46.