Portable cellphone based microbial pathogen detection system for water quality analysis

Abstract

We developed a digital nucleic acid amplification test (dNAAT) assay for the detection of indicator and pathogenic microorganisms at the point-of-sample collection. The system, named gLAMP, uses polyethylene glycol (PEG) hydrogel as reaction matrix and loop-mediated isothermal amplification (LAMP) technique for target DNA/RNA amplification (Fig. 1). The system achieved similar sensitivity to real-time PCR in virus quantification (Fig. 2), and demonstrated higher tolerance against inhibitors present in natural water samples (e.g., wastewater, stormwater and pond water). gLAMP is fast taking only 30 min from sample-to-answer compared to 2-4 h for real-time PCR and several days to weeks for traditional culture-based detection method. A smartphone based handheld incubation and detection device is under develop to facilitate the field scale application of the technol. Considering its simplicity, sensitivity, and rapidity, gLAMP holds great potential for microbial water quality anal. in some low-resource settings.