Synthetic Biologists Create Paper-Based Diagnostic for Ebola

Scientists say they can embed sophisticated genetic tests onto a piece of paper.

These slips of paper carry freeze-dried ingredients for simple scientific experiments.

Could complex genetic experiments one day be as simple to carry out as an over-the-counter pregnancy test?

Thats the idea behind new research from James Collins, a synthetic biologist at Boston University, who says hes been able to print the ingredients for simple DNA experiments on paper, freeze-dry them, and use them as much as a year later.

The work, described this week in the journal Cell by Collins and colleagues from Harvard, could lead to bandages that change color if an infection is developing, environmental sensors worn on clothing, or cheap diagnostics for viruses like Ebola.

The idea of inexpensive paper-based diagnostics isnt new. But so far, these tests have relied on traditional chemistry like pregnancy tests do (see Super-Cheap Health Tests and Paper Diagnostics). Collins says his work now extends the idea to precisely engineered genetic reactions.

The technology is an adaptation of a workhorse lab method known as a cell free system, in which the basic processes of a cellsuch as reading a DNA strand to make a proteinare carried out in a test tube.

The advance Collins made was to embed cell-free systems onto porous paper. His team added some essential enzymes as well as specially designed genes that make proteins, but only if theyre triggered by a matching strand of DNA or RNA.

Its a pragmatic, very big-deal improvement, says Julius Lucks, an assistant professor of chemical and biological engineering at Cornell University. Now we can ask What do we want to do [with it]?

Collins showed the system could detect the Ebola virus, whose genetic code consists of RNA. When his team added bits of Ebola RNA to paper test strips, the genetic material completed a circuit allowing production of a protein which stained the paper, causing it to turn dark purple in about an hour.

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Synthetic Biologists Create Paper-Based Diagnostic for Ebola