The amplification of a next generation sequencing (NGS) library is performed by PCR. In addition to increasing the amount of library, the PCR amplification step also enriches for fragments that have an adaptor ligated to each end, as the PCR primers hybridize to sequences included in the adaptors.
It is important that this PCR step does not introduce mutations or bias to the library.
FidelityWhen the sequencing process has a lower overall error rate, less sequence coverage is required, saving expense and time. Also, the exquisite sensitivity of NGS enables the detection of mutations present in samples, such as genomic DNA isolated from cancer tissues. Since such mutations can be present at low levels, it is important that mutations not be introduced during the library preparation process. The use of a high-fidelity DNA polymerase in library preparation results in more accurate sequencing data.
GC BiasGC bias can lead to uneven representation of some sequences within a NGS library.
This in turn can lead to
- Missing regions from assembled sequence
- Inaccurate sequence due to low coverage in certain areas
- Problems with sequence assembly due to uneven representation, including over-representation, of different sequence segments
NEB has developed high-fidelity polymerases to minimize bias and provide the highest fidelity commercially available. These products are available in our NEBNext library construction kits or separately as standalone reagents.
Several published reports have highlighted the GC bias of some polymerases in amplification of NGS libraries, leading especially to reduced representation of high-GC content regions such as 5 ́ untranslated regions (5 ́ UTRs) and CpG islands.
- Quail et al. (2011). Nature Methods 9(1):10-1.
- Oyola et al. (2012). BMC Genomics 13:1 doi:10.1186/1471-2164-13-1.
- Dabney and Meyer (2012). BioTechniques, 52(2): 87–94.
Products and content are covered by one or more patents, trademarks and/or copyrights owned or controlled by New England Biolabs, Inc (NEB). The use of trademark symbols does not necessarily indicate that the name is trademarked in the country where it is being read; it indicates where the content was originally developed. The use of this product may require the buyer to obtain additional third-party intellectual property rights for certain applications. For more information, please email firstname.lastname@example.org.
This product is intended for research purposes only. This product is not intended to be used for therapeutic or diagnostic purposes in humans or animals.