Development of Ball-Enabled Miniaturized Valves for Sample Preparation and Microheaters for Pathogen Detection

Abstract

There have been numerous Zika virus (ZIKV) outbreaks in the past few years, representing a public health problem. The recommended tests for the diagnosis of Zika infections are performed in a laboratory setting. However, diagnostics platforms at the point-of-care (POC) are highly desirable for understanding and preventing ZIKV transmission. To address this need, we have developed a testing platform that (1) can be operated in the field for pathogen detection, (2) is rapid, cost-effective, and reliable, and (3) does not require a power supply. To realize the platform, we have developed (1) a series of ball-based valves for the storage and sequential delivery of reagents and (2) microheater-enabled RNA amplification, both of which are integral components of this POC device. The multiple reagents are needed for virus lysis, RNA enrichment and purification. These ball-based are employed for fluid-control and they are actuated manually by sliding the unit and a pole under it, which can lift the balls. Nucleic acid amplification is then performed by a smart coffee mug that provides a constant temperature for reverse transcription loop mediated isothermal amplification (RT-LAMP), followed by colorimetric detection. We have demonstrated the detection of Zika virus in human urine and saliva samples using this testing platform.