CRI’s Sequencing Facility is a shared resource committed to enhancing research capacity for CRI and UT Southwestern scientists through the use of genomics-based technologies. The facility is equipped with an Illumina NextSeq 500 desktop Next Generation Sequencing (NGS) system optimized for high throughput, high speed and long reads.
Genomics-based technologies have revolutionized the way in which scientists approach questions in basic, clinical and translation research. NGS platforms enable a wide variety of applications, revealing limitless insight about the genome, transcriptome and epigenome of any organism.
Illumina NGS technology is based on massively parallel sequencing of millions of DNA fragments using reversible terminator-based sequencing chemistry. This technology relies on the attachment of randomly fragmented DNA to a planar, optically transparent surface. Attached fragments are extended and bridge-amplified to create an ultra-high density sequencing flow cell with millions of clusters, each containing hundreds to thousands copies of the same template.
These templates are sequenced using a robust two-color or four-color DNA sequencing-by-synthesis technology that employs reversible terminators with removable fluorescent dyes. High-sensitivity fluorescence detection is achieved using laser excitation and high speed scanning optics.
There are a number of standard library preparation kits that offer protocols for sequencing whole genomes, mRNA, targeted regions such as whole exomes, custom-selected regions, protein-binding regions, and more. In most of the protocols, the DNA is first fragmented into a library of small segments that can be uniformly and accurately sequenced in millions of parallel reactions.
The newly identified strings of bases, called reads, are then reassembled using a known reference genome as a scaffold (resequencing), or in the absence of a reference genome (de novo sequencing). The full set of aligned reads reveals the entire sequence of the DNA sample. Alternative sample preparation methods allow the same system to be used for a broader range of applications including gene expression, small RNA discovery and protein-DNA interactions.
UT Southwestern also has a Next Generation Sequencing Core Facility at the McDermott Center that provides UT Southwestern scientists with a wider array of sequencing platforms in conjunction with the Bioinformatics Platform.