Evolution of DNA Sequencing: From Sanger’s Method to Real-Time Clinical Applications]
Scientists first decoded DNA sequences in 1968. Over the following decades, researchers refined these methods, with Frederick Sanger’s chain-terminating sequencing approach using radiolabeled dideoxy nucleotides becoming the gold standard by 1977. The replacement of radiolabels with luminescent molecules in the subsequent two decades enabled next-generation sequencing.
As sequencing technology spread to more laboratories, researchers pursued increasingly ambitious goals. The Human Genome Project, launched in 1990 with a $10 billion budget, aimed to completely decode the human genome and drove further technological advances.
1995: Major Scientific Projects Lead to Leaps in Technology
During 1995, with the Human Genome Project underway, sequencing reached peak popularity. Scientists working on the project cloned short fragments of the entire genome and employed Sanger sequencing to determine nucleotide order, using multiple overlapping clones to create consensus sequences. However, this approach had limitations in the length of base pairs that could be sequenced at once and the technology available for running polyacrylamide gels and analyzing them.
To decode longer sequences faster and more reliably, companies introduced new gel polymer formulations and electrophoresis equipment to improve casting and temperature control. At the same time, manufacturers enhanced their sequencers to read longer fragments and automate experimental steps.
2007: A Celebrity Hard Launch for DNA Sequencing
In 2005, researchers from 454 Life Sciences promoted their new sequencing company by decoding the DNA of renowned geneticist James Watson, who agreed to the project enthusiastically. When Watson announced the project publicly, the researchers faced the challenge of meeting demanding standards as their sequencer struggled to produce sufficiently long and accurate reads. They eventually achieved 250 base pair reads with over 99 percent accuracy, delivering Watson’s complete genome on a DVD in 2007.
That same year, two biotechnology companies—454 Life Sciences and Illumina—helped scientists explore genomic questions about function and disease. While 454 Life Sciences’ long-read approach excelled at de novo sequencing, Illumina’s technology enabled researchers to run multiple short-read samples. These platforms advanced our understanding of epigenetics, metagenomics, cancer genes, and small RNAs.
2014: The (Sequencing) Price is Right
As sequencing technology advanced, costs dropped steadily. By the 2010s, no company had achieved whole genome sequencing for under $1,000—until Illumina introduced the HiSeq X in 2014, promising genomes at the coveted $1,000 price point, including reagents, equipment, and staff overhead. Although many institutions placed orders for the minimum 10-machine package priced at $10 million, some scientists noted that clinical interpretation costs remained unaddressed. Nevertheless, this milestone made sequencing more accessible to researchers.
2017: Sequencing Goes to Space
In 2016, microbiologist Kate Rubins became the first to sequence DNA in space, using a portable handheld sequencer on the International Space Station. After overcoming challenges of cell culturing and liquid pipetting in microgravity, Rubins completed the first off-world DNA sequence.
2018: Miniaturized Sequencer Provides Full Scale Readouts
Oxford Nanopore Technologies unveiled their pocket-sized MinION sequencer in 2018, capable of assembling a human genome. This miniaturized technology achieved sequencing reads of nearly one million bases, filling gaps in the human genome reference and making sequencing more accessible to scientists.
2023: Long-Read Sequencing Comes to Single Cells
As single-cell technology became more common for identifying rare cell variations and studying cell lineage, long-read sequencing also improved. Previously mutually exclusive due to insufficient DNA for long-read sequencing from single cells, researchers overcame this by suspending single-cell DNA fragments in droplet-based reactions with limited reagents, enabling DNA amplification for long-read sequencing without regional overrepresentation. This combination helped identify rare mutations in cancers and other disorders.
2025: Speeding Up DNA Sequencing to Get Clinical Results Stat
In neonatal intensive care units, rapid genetic testing guides clinical decisions, but existing methods often lag behind hospital timelines, sometimes taking days for results. Roche biochemist Mark Kokoris addressed sequencing speed limitations by converting DNA into a surrogate molecule that could be lengthened, then using metal oxide semiconductor sensors for rapid human genome sequencing.
Partnering with Broad Clinical Labs and Boston Children’s Hospital, researchers applied this approach to 15 neonatal samples. Results matched standard clinical diagnostic tests but returned findings in less than four hours, demonstrating sequencing’s potential to enhance clinical care.
