Without Electricity, DNA Purifier is Powerful Tool


the SNAP (System for Nucleic Acid Preparation) device
the SNAP (System for Nucleic Acid Preparation) device

A group of Boston University researchers, led by Assistant Professor Catherine Klapperich (ME) and Fraunhofer Gesellschaft researcher Paul Mirer, have designed a new powerless, handheld DNA extraction kit that may be a valuable tool in the battle against disease in rural communities. The thermos-sized device, named SNAP (System for Nucleic Acid Preparation), can extract genetic material such as DNA from blood and other bodily fluids without the need for electricity or refrigeration.

“This would allow personnel to prepare blood samples at the point of care,” Klapperich said. “It also allows for a longer window of time to move preserved samples to a central lab without the degrading the sample’s quality.”

Using a standard bicycle pump as power, SNAP extracts genetic material from bodily fluids by pumping fluid through a polymer-lined straw designed specifically to trap DNA. After the fluid sample is injected into the straw, pressure from the pump releases a lysis buffer, which breaks open the cell in the fluid. A second pump of air releases ethanol, which washes out everything but the DNA.

The straw, which was developed by a group led by Fraunhofer researchers Professor Andre Sharon (ME) and Alexis Sauer-Budge, is popped from the device, capped, and then stored as a dry sample that does not require refrigeration. The DNA, which remains stable at room temperature, can then be mailed to a central lab for investigation.

The SNAP device would be especially valuable in poorer, rural communities. To test for diseases such as HIV, blood samples from patients must be immediately refrigerated before transportation to a lab. In areas with scarce electricity, non-refrigerated blood can easily degrade and ruin the sample. With isolated DNA, the need for immediate, expensive refrigeration is eliminated.
“Ultimately I believe it will have the biggest impact as a disease surveillance tool,” Klapperich said. “And a huge step for using molecular diagnostics in the developing world. While it won’t be as quite as simple as a pregnancy test, it will make it significantly easier for people collecting samples.”

While a prototype has been used to isolate DNA from nasal wash samples infected with influenza A, the next step for the SNAP device is RNA isolation, which is significantly more difficult that DNA isolation. More unpredictable than DNA, RNA can only be stabilized for a much shorter period of time using current technology.

Through recent grants from the Innovations in International Health Initiative and the Program for Appropriate Technology in Health (PATH), Klapperich and Fraunhofer are developing a working prototype that can isolate both DNA and RNA and would be distributed over the next 24 months to medical personnel and scientists in the developing world.

“More research is needed to completely stabilize RNA,” Klapperich said. “We can stabilize it for a short period of time, but not long enough. All of research is geared towards stabilization. And when we do, it will be a huge piece of information that will change the way people are treated.”

A rendering of the SNAP device.
A rendering of the SNAP device.