I hate the phrase next-generation sequencing (NGS) with a passion. Here's why...
The first published use of this phrase (that I can find) is from an article in Drug Discovery Today: Technologies by Thomas Jarvie in 2005. This paper had the succinct title Next generation sequencing technologies, and while this may represent the first time this phrase made it into print, it certainly wouldn't be the last.
Illumina sequencing may be the most obvious technology that springs to mind when people think of NGS, but there is also Pyrosequencing (developed circa 1996), Massively Parallel Signature Sequencing (circa 2000), ABI SOLiD sequencing (circa 2008), and Ion semiconductor sequencing (circa 2010).
Of course we also have single molecule real time sequencing by Pacific Biosciences. They were founded in 2004 but didn't launch their PacBio RS machines until 2010. The current darling of the sequencing world is nanopore technology, something which has been in development since the mid 1990s.
So do we refer to this entire period (from development to finished technology) as the NGS era? If so, then NGS technologies have already been around for almost 20 years. It doesn't strike me as particularly helpful to keep on labeling all of these different technologies with the same name.
Some people have tried to make things clearer by introducing yet more levels of obfuscation. This has led to some of these technologies being referred to as either second generation, third generation, fourth generation, next-next-generation, and even next-next-next generation. And of course these definitions are all subjective and one person's third-generation technology is another person's fourth-generation technology.
Other alternatives to NGS such as high-throughput sequencing or long-read sequencing are equally useless because 'high' and 'long' are both relative terms. The output from a high-throughput sequencing platform of 2008 might seem like 'low-throughput' today. The weakness of length-based descriptions is the reason why the 'Short Read Archive' was (thankfully) reborn as the Sequence Read Archive.
So here is my proposed three-step solution to rid the world of this madness:
- Don't use any of these terms, ever again.
- Just refer to a technology by a name that describes the methodology (e.g. sequencing-by-synthesis) or by the name of a company that has developed a specific product (e.g. Oxford Nanopore).
- You could even just use the term 'current sequencing technologies'...as long as your paper/talk/blog/book has a date associated with it, then I'm confident people will know what you mean.
Update 12th March: I have added a follow-up post to this one.