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OHMX_High-throughput OMICS solutions

Exome
sequencing

Exome
sequencing

With our whole exome sequencing (WES) only the protein coding regions of the genome is targeted. The technique is a lot more cost effective than whole genome sequencing, allowing researchers to increase sample number, an important factor for large population studies.

WES does however have its limitations as it is based on probes capturing the protein coding sequences. Due to differences in the hybridization efficiency of these probes this can result in regions of the genome with little or no coverage. Additionally, WES suffers from reference bias as capture probes tend to preferentially enrich reference alleles at heterozygous sites producing false negative SNV calls.

Therefore, whole genome sequencing (WGS) is still preferable over whole exome sequencing as it allows you to interrogate single-nucleotide variants (SNVs), indels, structural variants (SVs) and copy number variants (CNVs) in both the ~1% part of the genome that encodes protein sequences and the ~99% of remaining non-coding sequences.

Advantages of Exome Sequencing

Reduced cost per sample as only the protein coding regions are targeted and sequenced

Reduced costs allow to sequence target regions at a higher depth at the same cost

Reduced costs make it feasible to increase the number of samples to be sequenced, enabling large population based comparisons

Exome Sequencing Workflow

Our wet-lab team always starts by performing a quality analysis of the DNA samples provided by you. We request at least 1µg of DNA. Only when the provided genomic DNA is of sufficient quality and quantity will we proceed with the next steps. In case the DNA provided to us is of insufficient quality and/or quantity, we will contact you and discuss how to proceed.

Then, the DNA contained within the exome will be captured, and sequencing libraries are prepared by ligating sequencing compatible adapters. After another quality assessment step these libraries are sequenced on one of our Oxford Nanopore Technologies sequencers. The technical quality of the sequencing run is monitored in real time.

Raw sequencing data can be transferred to you via the ohmX.bio server (FTP download) or the Illumina BaseSpace platform.