DNA-programmed blotting paper could soon be giving doctors a simple disease test that will reveal an infection in 30 minutes for just a few pence.
Researchers have proved the technique works by developing a prototype Ebola test in just 12 hours, and using just $20 of materials.
The smart diagnostics use a soup of biological ingredients including the genetic material RNA.
The researchers say this can be freeze-dried and preserved on ordinary paper.
Team leader Jim Collins, who has joint appointments at Boston and Harvard Universities, says the biological powder can be reactivated by simply adding water, like living powdered soup.
“We were surprised at how well these materials worked after being freeze dried,” he told the BBC.
“Once they’re rehydrated, these biological circuits function in these small paper disks as if they were inside a living cell.”
Genetic hacking
Jim Collins is a leading pioneer in the field of synthetic biology, whose 2000 paper showing genetic circuits could be created in the same way as electronic circuits can be programmed, helped launch the discipline.
Since then, synthetic biology has become a powerful tool in fundamental biology, with researchers hacking the genetic programmes of microbes to study their life processes, or give them the power to compute using logic like a digital processor.
Collins’ group has previously reprogrammed bacteria to become cellular spies, recording events as they pass through an animal’s bowels.
But the discipline has required specialist skills, so that few laboratories can take advantage of the techniques. The researchers’ avowed intention in the new work, described in the journal Cell, is to make synthetic biology widely available.
They’ve definitely succeeded, says Professor Lingchong You, an expert in cellular reprogramming at Duke University.
“This paper-based approach is incredibly attractive. It feels like you could use it in your garage! It’ll give scientists a synthetic-biology playground for a very low cost.”
‘Biochemical soup’
The materials in the powdered biochemical soup include simple enzymes that bacteria need, molecules to power the chemical reactions, amino acids which are the bricks of cell biology, and importantly ribosomes, giant molecular machines that read genetic material and use it to assemble the bricks into functioning proteins.
In liquid form, these cell extracts are routinely used in biology labs. Linchong You gives credit to Collins for having the imagination to freeze dry them with synthetic genes.
“With hindsight, it’s obvious it should work. But most of us don’t think in this direction – there was a real leap of faith. But the fact you can leave these freeze-dried systems for a year, and they’ll still work – that’s quite remarkable.”
Credit: BBC