P193 Development of a handheld point of care molecular diagnostic device for sexually transmitted infections

Abstract

<h3>Background/introduction</h3> Brunel DoCLab is part of the <i>e</i>STI2 Consortium which is developing electronic self-testing and portable instruments for sexually transmitted infections using nucleic acid amplification test technologies. We have designed a point of care test platform that integrates a proprietary sample collection device directly with a microfluidic cartridge. A low cost benchtop real-time isothermal amplification platform has been developed capable of running six amplifications simultaneously. <h3>Aim(s)/objectives</h3> To evaluate the sample preparation and isothermal amplification within the low cost diagnostic platform. <h3>Methods</h3> The microfluidic device incorporates passive mixing of the lysis-binding buffers and sample. Cell lysis, within the cartridge, is conducted using a chemical method and nucleic acid purification is done on an activated cellulose membrane. Isothermal amplification was conducted using recombinase polymerase amplification (RPA). <h3>Results</h3> Preliminary results have shown extraction efficiencies for this new membrane of 69% and 57% compared to the commercial Qiagen extraction method of 85% and 59.4% for 0.1 ng/µL and 100 ng/µL salmon sperm DNA respectively spiked in phosphate buffered solution. Extraction experiments in the passive mixer cartridges with lysis and nucleic acid purification showed extraction efficiency around 80% of the commercial Qiagen kit. The platform is capable of detecting <i>Chlamydia trachomatis</i> genomic DNA within 10 min using RPA for 100,000 copies/µL. <h3>Discussion/conclusion</h3> The work presented here shows a low cost, rapid nucleic acid extraction, isothermal amplification and detection platform for diagnosing C. trachomatis. Work is on-going to fully integrate the sample-in to result platform for rapid diagnosis of STIs using genital samples.