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This work presents a low-cost transcription loop-mediated isothermal amplification (RT-LAMP) instrument for nucleic acid detection, employing an Arduino Nano microcontroller. The cooling system includes customized printed circuit boards (PCBs) that serve as electrical resistors and incorporate fans. An aluminum block is designed to accommodate eight vials. The system also includes two PCB heaters—one for sample heating and the other for vial lid heating to prevent condensation. The color detection system comprises a TCS3200 color 8-sensor array coupled to one side of the aluminum heater body and a white 8-LED array coupled to the other side, controlled by two Multiplexer/Demultiplexer devices. LED light passes through the sample, reaching the color sensor and conveying color information crucial for detection. The top board is maintained at 110 ± 2 °C, while the bottom board is held at 65 ± 0.5 °C throughout the RT-LAMP assay. Validation tests successfully demonstrated the efficacy of the colorimetric RT-LAMP reactions using SARS-CoV-2 RNA amplification as a sample viability test, achieving 100% sensitivity and 97.3% specificity with 66 clinical samples. Our instrument offers a cost-effective (USD 100) solution with automated result interpretation and superior sensitivity compared to visual inspection. While the prototype was tested with SARS-CoV-2 RNA samples, its versatility extends to detecting other pathogens using alternative primers, showcasing its potential for broader applications in biosensing.
Details
Software;
Nucleic acids;
Gene amplification;
Aluminum;
Severe acute respiratory syndrome coronavirus 2;
Heating;
Ribonucleic acid--RNA;
Circuit boards;
Biosensors;
Heat;
Colorimetry;
Color;
Low cost;
Sensitivity;
Cooling systems;
Pandemics;
Sensors;
Organic light emitting diodes;
Sensitivity analysis;
Sensor arrays;
RNA-directed DNA polymerase;
Methods;
Phenols;
Multiplexer demultiplexers
; Stracke, Mateus Cassaboni 1
; Heloisa Bruna Soligo Sanchuki 2
; Viviane Klassen de Oliveira 3
; Ancelmo, Hellen Cristina 1
; Bordin, Dayanne Mozaner 4
; Marchini, Fabricio Klerynton 1 ; Emilson Ribeiro Viana 5 ; Blanes, Lucas 1
1 Laboratory for Applied Science and Technology in Health, Carlos Chagas Institute, Oswaldo Cruz Foundation (Fiocruz), Professor Algacyr Munhoz Mader 3775 St., Curitiba 81350-010, Brazil;
2 Laboratory for Applied Science and Technology in Health, Carlos Chagas Institute, Oswaldo Cruz Foundation (Fiocruz), Professor Algacyr Munhoz Mader 3775 St., Curitiba 81350-010, Brazil;
3 Paraná Institute of Molecular Biology, Professor Algacyr Munhoz Mader 3775 St., Curitiba 81350-010, Brazil;
4 School of Mathematical and Physical Sciences, Faculty of Science, University of Technology Sydney, Ultimo, NSW 2007, Australia
5 Academic Department of Physics (DAFIS), Federal University of Technology—Paraná (UTFPR), Sete de Setembro 3165 Av., Curitiba 80230-901, Brazil;