Next Generation Sequencing

Next-generation sequencing technologies primarily work by combining short reads from fragmented DNA through step-by-step cycles of polymerase-based extension or oligonucleotide ligation. However, the most recent methods for next-generation sequencing testing can generate longer reads from segments of DNA nucleotide strands that are significantly larger.

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There are two tried-and-true methods for delivering long-read sequencing. In the first method, known as nanopore sequencing, the strands are passed through a protein nanopore while electrical current changes are recorded for each base. The sequence is then decoded by a computer using these modifications. In the second method, known as single-molecule real-time (SMRT) sequencing, the strands are circularised and tagged bases that emit light upon integration are incorporated using a polymerase. Real-time measurements of nucleotide incorporation are made using the light that is detected.

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​New development frontiers are broken in next-generation sequencing technologies on an almost annual basis. The most recent advancements incorporate single-cell sequencing, which avoids ensemble average readings from a sample, which may be deceptive and provides more accurate insight into the nucleic acids of specific cells during a given phase or time point. Spatial sequencing, a new method for directly sequencing from a tissue or sample, gives researchers a spatial resolution to their data and an understanding of the makeup and interactions of the cell in its natural environment.