Exome sequencing is invaluable for sequencing only the coding regions of the human genome. With exons representing only 3% of the genome, it is critical to have an effective method of separating these regions from non-coding DNA to focus on potentially important mutations implicated in disease. The captured material must also be suitable for sequencing to a satisfactory depth of coverage for reliable detection of variant alleles.
The xGen Exome Research Panel consists of 5′ biotin–modified oligonucleotide probes that are individually synthesized and individually analyzed by electrospray ionization mass spectrometry (ESI-MS) and OD measurement. The probes are then normalized before pooling to ensure that each probe is represented in the panel at the correct concentration. Probes that fail quality control are resynthesized. This rigorous manufacturing process gives the xGen Exome Research Panel a unique advantage over array-derived pools, in which missing or truncated probes cannot be identified before sequencing. Using IDT proprietary synthesis methods, even probes with high GC and AT content are appropriately represented in the panel.
To provide increased depth of coverage and enable high multiplexing of samples, the xGen Exome Research Panel targets only the coding sequences (CDS) of human coding genes in the RefSeq database.