Long regions enrichment

A multiplex enrichment adds coverage breath when capturing long regions

Xdrop® indirect sequence capture lets you enrich staggered long DNA molecules to cover long regions

  • Ensure that every portion of your region of interest is well represented in the enrichment

  • Examine regions of interest that are longer than 100 kb

  • Achieve evenly deep sequencing coverage of a very long region of interest


Analyses to characterize rare genomic sequences call for heightened sensitivity. Low-frequency haplotypes in tumor tissue samples or low-abundance populations in microbial communities are some examples. Xdrop efficiently enriches DNA molecules that contain a part or the complete region of interest which serve as input material for deep sequencing coverage.

The single-molecule resolution of Xdrop also helps reveal low frequency variants and allows haplotype phasing. But you can easily augment the scope of the genomic region examined by simply multiplexing the indirect sequence capture. Here are a few examples.

Deep sequencing a 70 kb region including the TP53 gene

Our collaborators at SciLifeLab and the Cancer Center at Karolinska Institute evaluated the performance of Xdrop in phasing mutations in heterogenous samples from chronic lyphocytic leukemia patients. They used a five-plex strategy to enrich a collection of long DNA fragments that collectively spanned the entire length of TP53. Deep sequencing coverage allowed them to phase 3 point mutations and the wildtype sequence in a single patient – all on different alleles! Find out more

TP53 multiplex

A simple design with the power to go beyond 100 kb

Looking to benchmark the performance of Xdrop, we enriched long DNA fragments around a Detection Sequence within the BRCA2 gene. The length of BRCA2 and the position of the Detection Sequence resulted in low coverage of the upstream portion of the gene. By simply adding a second set of primers in the same capture reaction – a duplex enrichment – we expanded the input material for sequencing to cover the complete gene. Get the details on this and several other milestones of the Xdrop workflow in this Technical Note.

brca2 duplex(2)

Do you want to know more? 

The power of Xdrop® lies in its emphasis on single long DNA molecules and its simple design. Single-molecule resolution delivers sensitivity. Simple design opens endless application options. Where will you take Xdrop?