The NHS is using DNA sequencing to work out what is making you ill
Key Points
- NHS hospitals ran around 5,000 patient samples through DNA sequencing in the first half of 2026 to identify infections.
- The NHS Metagenomic Network of Excellence has expanded to 18 sites.
- A pilot at Guy's and St Thomas' returned results in a median of 6.7 hours and changed antibiotics for nearly half of patients on day one.
- Oxford Nanopore has registered GridION Dx, its first device certified for diagnostic use in the UK and Europe.
- A validation study at Oxford University Hospitals found the method less reliable for viruses in upper respiratory samples.
NHS hospitals put around 5,000 patient samples through DNA sequencing in the first half of 2026 to identify the infections behind them.
The NHS Metagenomic Network of Excellence has grown to 18 sites, according to interim results published by Oxford Nanopore Technologies on Wednesday (19 August). The Oxford company supplies the sequencing technology behind the programme.
Standard microbiology grows a sample in a laboratory and waits to see what appears, which takes between 24 and 72 hours and returns nothing at all in up to two thirds of probable sepsis cases.
Metagenomic sequencing reads every strand of DNA in a sample instead, then matches what it finds against a database of known bacteria, viruses and fungi.
The same reading also picks up antibiotic resistance genes, so clinicians can see which drugs the organism will shrug off before they prescribe.
A pilot at Guy’s and St Thomas’ NHS Foundation Trust tested the approach on critical care patients with suspected respiratory infections. The trust reported a median turnaround of 6.7 hours from sample to result, and clinicians changed the antibiotics of almost half the patients on the first day.
The government funded an expansion of the programme in 2024, extending pathogen-agnostic surveillance to as many as 30 NHS England hospitals. That network doubles as an early warning system for new pathogens, flagging organisms that no existing test would have looked for.
Great Ormond Street Hospital has run a related service since 2014, accredited in 2024, which searches for infection in tissue and sterile sites after conventional tests come back negative.
A validation study at Oxford University Hospitals has found some limits to the method. Testing upper respiratory samples for viruses, the workflow detected 51% of the infections that PCR picked up, rising to 83% once samples with very low viral loads came out of the count, at a cost of £112 per sample. Reliability improved when more of the virus was present.
Oxford Nanopore has since registered GridION Dx, its first device to carry CE and UKCA certification as an in vitro diagnostic.
The certification covers the UK and Europe and allows hospitals to use the device in regulated clinical testing rather than research alone.
