Engineering Minute

Engineering Minute – Portable, Rapid Blood Test for Infectious Disease

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Researchers at Purdue University are working on developing a type of rapid test for infectious diseases, such as HIV. The handheld device is made of paper and can detect HIV specific nucleic acids from a single drop of blood within 90 minutes. Since the test is both affordable and portable, it could open the doors for at home HIV testing. The team hopes that the technology could be applicable to other infectious diseases like whooping cough and cholera. 

 

"The idea is to more quickly detect what's causing an infection for patients both in areas of the world that have the lab facilities close by and those that don't," says Jaqueline Linnes, assistant professor of biomedical engineering at Purdue University.

 

 

From the Purdue University article: "This means that paper can carry samples, such as blood or water, without all the external equipment required within a lab to separate out the nucleic acids of a pathogen and make copies, or "amplify" them, for detection.

'"Paper" is a broad term for a porous material that can pull liquid along, not just the type that you can write on. Band-aid pads are paper-like, for example,' Linnes said. 'The downside is that paper doesn't have any controls.'

For this reason, most paper-based devices relying on nucleic acid amplification are still in very early stages. Linnes' lab has been working to speed up how these devices operate in the field by reducing the number of steps needed to separate pathogens from a sample loaded onto paper.

So far, Linnes' lab and other researchers at Purdue have reduced these steps through an electronic circuit board that heats wax valves from beneath intricate channels of paper, controlling the flow of a sample in one step rather than multiple steps. The process starts with adding buffer liquid to a finger prick of blood within a vial, and then pouring the vial into a hole within the paper.

If a band shows up on the end of the paper strip after a sample has been loaded, in addition to the control band, then a person has tested positive for a disease."

Read more about the portable, rapid test for infectious disease at Purdue University