We report the development of a low-cost mobile nucleic acid analysis platform (mobiLab) utilising a smartphone-enabled microfluidic device for streamlined analysis of biological samples. Using magnetic particles as a mobile solid phase for nucleic acid capture and transport, fluidic processing is simplified to particle translocation on a robust and scalable cartridge.

Process integration facilitated by Bluetooth-enabled microcontrollers enables full control of the instrument by the user with a smartphone application. Each cartridge costs less than $2 using off-the-shelf reagents and materials, an order of magnitude cheaper than $9.98/test for a GeneXpert cartridge. The instrument utilises a microcontroller which controls the rotary bead manipulator, thermal incubation and Bluetooth-based communication with the smartphone application. Each assay consumes approximately 10% of the battery capacity, allowing up to 10 assays to be performed consecutively without access to a power outlet.

We designed a single-stream loop-mediated isothermal amplification (LAMP) assay to operate in tandem with the mobiLab platform. We tested the single-stream assay using plasmid targets and were able to capture and amplify 10³ copies of gene targets. Absence of cross-reactivity with human genomic DNA or other vaginal flora was verified.

The platform was validated by testing Chlamydia trachomatis infection from patient-collected vaginal swab samples. Volunteers enrolled in an internet-based Chlamydia screening program, where two sets of swabs were self-collected and mailed back to our lab. One set of swabs was analysed using the gold standard Gen-Probe AC2 CT assay. The second set of swabs was tested using the mobiLab platform. The two results were in agreement for 20 out of 20 samples at a time threshold of 30 min, demonstrating that the droplet assay performance is comparable to the gold standard for the samples tested. To our knowledge, this abstract presents the first smartphone-based NAAT platform that integrates sample preparation, amplification and data processing.

Disclosure of interest statement None to disclose.