Abstract

A paper/plastic hybrid microfluidic device for rapid nucleic acid extraction and amplification of DNA on a low cost platform

Ruth Mackay, Lecturer, Brunel University

Brunel DoCLab is part of the esti2 consortium developing electronic self-testing instruments for sexually transmitted infections using nucleic acid amplification testing (NAAT). A proprietary sample collection device has been designed to integrate directly with a microfluidic cartridge. Cell lysis was conducted using a chemical method and nucleic acid purification was done on an activated cellulose membrane. A PMMA microfluidic device, with an activated paper insert for nucleic acid extraction, incorporates passive mixing of the lysis-binding buffers and the sample. Preliminary results have shown extraction efficiencies for activated paper membrane of 69% and 57% compared to the commercial Qiagen extraction method of 85% and 59.4% for 0.1ng/µL and 100ng/µL salmon sperm DNA spiked in phosphate buffered solution [1]. Isothermal amplification was conducted using thermophillic helicase dependant amplification [2]. Helicase dependant amplification assays have been developed for detection of Mycoplasma genitalium and other sexually transmitted diseases. A low cost platform has been developed integrated joule heating and optical detection. The Arduino platform is used for automated fluidic and thermal control as well as communication of results. Work to integrate sample collection, nucleic acid extraction and isothermal amplification is currently underway.