Researchers at Purdue University have developed a device that facilitates the more convenient detection of pathogens across healthcare environments, farms, and food production facilities. The scientists detailed the new system in the IEEE Sensors Journal.
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The device marks an advancement in the suite of tools that are available to conduct molecular assays in the field. Due to its versatility and ease of use, it has the potential to be applied across multiple fields.
Mohit Verma, Associate Professor, Agricultural and Biological Engineering, Purdue University
The latest research describes the development of a system known as IsoHeat for processing those test samples.
This project was mainly about hardware, fabricating the water bath system to process our biological samples.
Nafisa Rafiq, PhD Candidate, Biomedical Engineering, Purdue University
The researchers designed the device to perform an assay known as loop-mediated isothermal amplification (LAMP). Developed 25 years ago, LAMP identifies microbes by amplifying – creating additional copies of – target nucleic acids. The chemical reaction occurs at a single, constant temperature, enabling detection of any pathogen or nucleic acid target, including antimicrobial resistance.
“We aimed to make the system portable, having uniform heat distribution throughout the water while heating and allowing the user to observe continuous changes with the naked eye,” Rafiq and Verma added. “The ease of use, precise temperature control in a sealed setup, and visual monitoring of LAMP assays make our device novel and ideal for rapid on-farm molecular diagnostics.”
Rafiq and Verma evaluated their IsoHeat device against a commonly used piece of equipment for heating LAMP assays in field settings. IsoHeat achieved the target temperature of 149 º F (65 ºC) in approximately 12 minutes. In comparison, the commercially available precision cooker used for testing required about 36 minutes to reach the same temperature.
Further, as Rafiq and Verma stated in their study, “IsoHeat was specifically designed to be operated by nonspecialists in the field or low-resource settings.”
Building on her undergraduate background in industrial engineering, Rafiq produced multiple components of the tabletop device using 3D printing and laser-cutting methods. The completed system primarily comprises an electrical unit that heats and maintains water at the required temperature, along with the associated hardware and a power supply.
“The initial challenge that I faced was to select the optimized material to fabricate. We needed to think about cost-effectiveness. Also, we needed to think about portability. It must be light and easy to manage for the end user to transport.”
As the system is electrical and involves water, “we had to make sure above everything that the system is completely safe and user-friendly.”
Convenience features include a sealed container for consistent heating, a suspended sample holder, and easy-to-use touchscreen controls. The device removes the need to secure samples to the container wall in hot water while wearing protective gloves.
“We can prepare biological samples and then use our system to process those samples and get our output anywhere,” Rafiq said.
This research was supported by the Foundation for Food and Agriculture Research, the U.S. Department of Agriculture, the Wabash Heartland Innovation Network, and an Agricultural Science and Extension for Economic Development grant from the Purdue College of Agriculture.
Journal Reference:
Rafiq, N., & Verma, M. S. (2025) Design and Development of a Field-Deployable Water Bath for Loop-Mediated Isothermal Amplification Assay. IEEE Sensors Journal. DOI: 10.21227/66we-r070. https://ieeexplore.ieee.org/abstract/document/11085117.