What are Unique Molecular Tags?

 

Kristine Angevine, PhD, Product Manager I on October 6, 2016

Recently, Rubicon Genomics announced exciting news at AGBT’s Precision Medicine Conference–the launch of our ThruPLEX® Tag-seq Kit, a NGS library preparation kit with unique molecular tags (UMTs)! You might be thinking to yourself, “That’s great, but what are UMTs and why would I need them?” I’m here to help! Today I’m going to provide more details to help you understand what UMTs are, how they work and how they can be applied to your research.

What are UMTs?

UMTs are unique sequences used to tag individual DNA fragments prior to amplification, providing tracking of the fragments through the library preparation, target enrichment and the data analysis processes. In each ThruPLEX Tag-seq Kit, over 16 million UMTs are provided in order to ensure unique labeling of every fragment.

How do UMTs work?

For the ThruPLEX Tag-seq Kit, we designed our proprietary stem-loop adapters to contain a UMT sequence made up of degenerate bases. The molecularly tagged adapters are incorporated during the ligation step of the library preparation process to label the starting DNA molecules. This allows the sequencing reads to be grouped during data processing into amplification families based on their UMTs. Through bioinformatics analysis, the reads within each amplification family are compared and PCR artifacts and sequencing errors are removed to form a consensus sequence.

How can I use UMTs in my research?

UMTs can be useful in a lot of situations. Research in next-generation sequencing (NGS) is rapidly evolving, and the ability to confidently detect low-frequency alleles or differentiate between molecules is now critical to the development of highly sensitive, NGS-based assays. UMTs provide two major utilities – error correction and molecular de-duplication. In NGS, errors are introduced during PCR, sequencing and base calling. The additions of UMTs allow removal of errors to reduce background noise and false-positive rate, allowing you to confidently detect rare alleles with high sensitivity and specificity. In addition, since the UMTs label each DNA fragment at the beginning, bioinformatics solutions allow you to remove PCR duplicates, distinguish molecular duplicates, and consequently obtain a true count of the starting molecules. This provides true coverage information of the genomic regions of interest.

 

Still confused by UMTs? Check out this video to learn more!

 

For more information please contact sales@rubicongenomics.com