Tuberculosis Diagnosis Using Isothermal Nucleic Acid Amplification in a Paper-and-Plastic Device

Abstract

Nucleic acid (DNA/RNA) amplification technologies are indispensable for applications like disease diagnostics, forensics, epidemiology, evolutionary biology, vaccine development, and therapeutics. While polymerase chain reaction (PCR) has deeply penetrated the abovementioned fields and has been commercially successful, two major common disadvantages are exorbitant costs of associated equipment, which create concerning roadblocks in terms of affordability and accessibility. This work describes development of an inexpensive, portable, easy-to-use and deliverable-to-end-users, nucleic acid amplification technology for infectious disease diagnosis. The device uses loop-mediated isothermal amplification (LAMP) and cell phone-based fluorescence imaging to enable nucleic acid amplification and detection. A regular lab incubator and a custom-made low-cost imaging box are the only two additional equipment required for testing. Material cost for a 12-test zone device was $0.88, and cost of reagents per reaction was $0.43. First successful application of the device was demonstrated for tuberculosis diagnosis with clinical sensitivity of 100% and clinical specificity of 68.75% for testing of 30 clinical patient samples.

Keywords: Global health; Loop-mediated isothermal amplification (LAMP); MicroPAD; Nucleic acid amplification test (NAAT); Paper analytical devices; Tuberculosis.