Voice-Activated Sample Pre-Treatment Device Enables Hands-Free, Safer DNA Handling

Scientists using samples containing pathogens work with the smallest amounts possible in order to avoid accidental infection. In the case of highly contagious bacterial diseases, on-site sample analysis is suitable for rapid diagnoses. Additionally, scientists with visual or other physical impairments can find it difficult to operate complex instruments, particularly those designed for tiny volumes. Now, the same technology used by smart voice assistants could also make the laboratory a safer place for scientists and technicians handling infectious samples.

Hands-free devices that can be operated quickly using voice commands could make the laboratory safer for scientists and technicians. Researchers at Kyung Hee University (Yongin, South Korea) set out to combine a speech recognition app with a miniaturized extraction system to do just that. The researchers first built a microfluidic chip with multiple chambers linked together by six 3-way solenoid valves, which were operated by a micro-controller connected to a Bluetooth module. The palm-sized device weighed only 11 ounces and was powered by a portable battery or a 5V smartphone charger. Using existing speech recognition software, the team went on to customize a smartphone app to listen for specific voice commands.

Image: The small, voice-activated device extracts and pretreats bacterial DNA (Photo courtesy of ACS Sensors)

The voice-activated system is simple to operate. As soon as the user says one of the operation commands out loud, the app wirelessly sends an initiation signal to the micro-controller. After receiving the signal, the micro-controller automatically begins a series of steps, including sample loading, washing and releasing the purified DNA into a collection chamber. Currently, the system requires the user to touch the smartphone to start the speech recognition software, although the entire operation could soon become completely hands-free with the addition of virtual assistant software.

The researchers conducted tests of the system in which the voice-controlled device extracted DNA from Salmonella Typhimurium, purifying a 10-µL sample with an efficiency of 70% in less than a minute. The system’s performance was lower as compared to a traditional DNA extraction kit, although its voice control, portability and quick automation lend it an advantage for convenient and safe bacterial DNA testing, according to the researchers.

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Kyung Hee University