Next generation sequencing: a fit-for-purpose tool


NSF International, USA


Next Generation Sequencing (NGS) expands testing options within the food, dietary supplement and spice industries over traditional Sanger sequencing by increasing throughput. Several methodologies in NGS (whole genome sequencing, 165rRNA metagenomics, shotgun metagenomics, targeted gene sequencing, RNA-SEQ) are useful in DNA barcoding for species identification and differentiation in commercial products. While certain processing techniques can significantly impact the DNA sample (eg. sterilization), NGS can prove beneficial in reducing the risk of adulteration. NGS can be a useful tool, especially when applied with chemical identification and DNA sequencing to provide a more complete assurance of product safety and quality.

Next Generation Sequencing (NGS) has not only changed sequencing technology, but has also expanded testing options within the food, dietary supplement, and spice industries. Evolving from first generation Sanger sequencing, NGS provides in-depth results, a higher throughput of samples, and a lower cost than traditional methods. NGS is currently the most widely-utilized technology in the genomics field (2). Using this one testing methodology, we are able to sequence small portions of a genome, or sequence the entire genetic make-up of an organism. NGS is able seek out one organism’s DNA but can also detect DNA from all organisms within a sample.

Sequencing’s first significant breakthrough occurred in 1977 when Frederick Sanger developed the chain termination method now called Sanger sequencing. In this method, di-deoxy NTPs are labeled with fluorescent dyes. These di-deoxy NTPs terminate the extension reaction when incorporated via polymerase chain reaction (PCR). The end of each fragment has a fluorescent signal that is run through a capillary gel in order to visualize the strands. Using the position in the gel and the color of the signal, the gel res ...