A low-cost PCR instrument for molecular disease diagnostics based on customized printed circuit board heaters.
Biomed Microdevices
; 23(2): 24, 2021 04 14.
Article
em En
| MEDLINE
| ID: mdl-33855638
ABSTRACT
This article describes the fabrication of a low-cost Polymerase Chain Reaction (PCR) instrument to detect diseases. In order to reduce the instrument price and simplify construction we developed an alternative fabrication process, transforming conventional printed circuit boards (PCB) in heating elements, avoiding the use of aluminum heating/cooling blocks and Peltier devices. To cool down the reaction a simple computer fan was used. The vial holder was fabricated using two double side PCB boards assembled in a sandwich-like configuration. The bottom PCB has a resistance of 0.9 Ω used to heat the reaction mix, while the top layer has a resistance of 1.1 Ω to heat the vial body, preventing vapor condensation. The top board was maintained at ~ 110 ± 1 °C during all cycles. The final device was able to heat and cool down the reaction at rates of ~ 2.0 °C/s, a rate comparable to commercial thermocyclers. An SMD NTC thermistor was used as temperature sensors, and a PID (proportional-integral-derivative) control algorithm was implemented to acquire and precisely control the temperature. We also discuss how the instrument is calibrated. The device was tested successfully for the amplification of T. pallidum (Syphilis) bacterial DNA and Zika virus RNA samples, showing similar performance to a commercial PCR instrument.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Zika virus
/
Infecção por Zika virus
Tipo de estudo:
Diagnostic_studies
/
Health_economic_evaluation
Limite:
Humans
Idioma:
En
Revista:
Biomed Microdevices
Assunto da revista:
ENGENHARIA BIOMEDICA
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Brasil