Current Open-Source LAMP hardware

Funded by previous open hardware calls, we have already developed an open-source hardware to perform Real Time LAMP (Loop-Mediated Isothermal Amplification) by measuring the fluorescent signal as the reaction happens. Despite having enabled local researchers and producers to detect human viruses, presence of GMOs in agriculture or measure the activity of locally produced LAMP enzymes, the hardware does still have limitations.

 

Open qLAMP: an open source isothermal fluorimeter for Real Time LAMP experiments

 

Benchmark of the Open qLAMP against a commercial thermocycler for the quantitative detection of transgenes in agricultural crops

While the device is two orders of magnitude cheaper than commercial alternatives, it still costs around $60 to produce, hampering its production in large scale on low resouce settings. Although it is portable and potentially powered by an external battery, the device is sensitive to the rigors of travel, during which the optics or various internal components of the machine may become misaligned. A simpler, more portable, and cheaper hardware solution is needed so it can be distributed on a larger scale for on-site sampling in remote regions. We envision being able to take qualitative measurements (simple 'yes' or 'no' readings at the end of the reaction) while moving through the field. If a sample tests positive, then that specific one can then be taken for further detailed analysis upon returning to the lab. Our initial approach involved a 3D-printed water bath (created with resin to withstand the heat), which incubated the samples at 63ºC and subsequently illuminated the internal chamber with a series of side LEDs. If the reactions are positive they will fluoresce in green, and a filter on top of the device will allow the fluorescence to be seen with the naked eye.

 

3D printed waterbath with lyophiled reactions

 

Waterbath benchmark against a commercial thermocycler for the detection of 2, 20 and 200 copies of inactivated SARS-CoV-2.

Nevertheless, there is still room for improvement. Although it costs to produce five times less than the previous hardware, it is still far from reaching the production cost of the rapid lateral chromatography tests that we aim to replace. Despite its simplicity, the combination of water and electronics presents handling risks. It's relatively easy for the device to become wet, potentially damaging the electronics. Although the design is intended for production via digital fabrication techniques, its assembly is largely manual and homemade. This is particularly true for the construction of the thin sidewall that separates the LEDs from the internal chamber, which poses challenges for mass production.

This inspired us to push the design further. Instead of merely refining the current water bath model, we're setting our sights on an entirely new device—one that is simpler, sturdier, and more affordable. Our mission is to surpass the current lateral flow tests with a minimal hardware that allows for on-the-go nucleic acid amplifications at a cost of less than $3, all without being disposable and while maintaining the accurate detection range characteristic of isothermal amplifications. We imagine a minimalist design, ideally based on a single PCB, on which fit the tubes, 8 blue LEDs and an inexpensive LEE filter, which heats up to 63ºC and is able to incubate the reactions on its own. Our ultimate aim is to broaden access to diagnostic technology, particularly in remote and underserved regions that are in dire need of such advancements.