Experimental demand and the increasing capacities of next generation sequencing (NGS) platforms have resulted in sample multiplexing becoming commonplace. Multiple samples are sequenced simultaneously with the help of sample indexes that are part of the adapters added to DNA during library construction. The indexes are specific to each sample in the experiment and are used to assign millions of sequence reads to the correct samples during data analysis. Unfortunately, multiplexing comes with a risk of false assignment of sequences to their samples of origin. This can impact several applications, including low-frequency somatic variant detection, ancient DNA research, viral detection, microbial profiling, and gene expression studies.
Different strategies employing index sequences have been developed to avoid these misassignments and to increase the accuracy of multiplexing in NGS applications. Some of these strategies include a unique molecular identifier (UMI) within the adapter to correct for PCR and sequencing errors. When a UMI is added, reads are assigned to each sample based on their associated sample index, and the UMI is used for error correction during data analysis. A single adapter that is suitable for a variety of applications and needs of individual researchers would be ideal. IDT xGen® Dual Index UMI Adapters—Tech Access meet these requirements. In addition to unique, dual indexes, the adapters contain a molecular identifier in an optional read position.
xGen Dual Index UMI Adapters—Tech Access take the guesswork out of adapter design and ordering. These adapters, created for Illumina sequencers, are compatible with standard library preparation methods and may be sequenced in different modes depending on your application.
In the below webinar, entitled “Dual index adapters with UMIs resolve index hopping and increase the sensitivity of variant detection,” Dr Nick Downey explains how unique, dual indexes mitigate sample index hopping for multiplexed sequencing. Dr Downey also demonstrates how UMIs reduce false positives to improve detection of low-frequency variants.
For more information on these adapters, view the webpage xGen Dual Index UMI Adapters—Tech Access.
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