Design Of Temperature Control System For Nucleic Acid Hybridization And Amplification

Nucleic acid amplification technology and nucleic acid hybridization technology are not only the crucial technologies in scientific research of molecular biology and related disciplines,but also the common means used by medical units for disease diagnosis.They have played a huge role in the detection of the COVID-19 epidemic.Nucleic acid amplification technology is divided into isothermal and variable temperature amplification.Nucleic acid hybridization technology is generally isothermal,indicating that temperature control technology is very important for molecular detection.In this paper,a temperature control system for nucleic acid amplification and hybridization technology has been designed and developed,and a nucleic acid variable temperature amplification device and a nucleic acid constant temperature hybridization device have been built.Nucleic acid variable temperature amplification temperature control system(variable temperature system): Thermodynamic simulation analysis of important heating and heat dissipation components using solid heat transfer physical fields is conducted to optimize and improve the temperature uniformity of the model structure based on the results.The radiator is simulated in the order of considering only solid heat transfer and solid and fluid heat transfer to determine the impact of the number of radiator fins on the heat dissipation effect of the radiator.STM32F103VET6 is used as the main control chip to design the minimum system.The H-bridge circuit can change the direction of the current to control the heating and cooling modes of the semiconductor cooling chip.The drive circuit and voltage stabilizing circuit are optimized to improve the stability of the hardware circuit;The transfer function of the temperature control system is established,and the parameter values of the transfer function are determined using the step response identification method.The particle swarm optimization method is used to optimize the initial values of fuzzy PID control parameters,and then the adaptive characteristics of fuzzy control are used to control the system.A particle swarm optimization fuzzy PID controller is designed;Using a serial port screen to achieve human-computer interaction,using TTL serial port to communicate with the main control board,and using SPI communication for system data transmission;A nucleic acid variable temperature amplification device was designed and constructed.Nucleic acid constant temperature hybridization system(constant temperature system):Thermodynamic simulation analysis of heating components to optimize the model structure;Design a voltage stabilizing circuit to provide a stable working voltage for the strip resistor,improving circuit stability;The same control algorithm is used for temperature control as the variable temperature system;Adopt CAN communication mode for data transmission;A nucleic acid constant temperature hybridization device was designed and constructed.The experimental verification results show that the heating rate of the variable temperature system reaches 6.648 ℃/s,the cooling rate reaches 5.22 ℃/s,the temperature uniformity is ± 0.2 ℃,and the temperature control accuracy is ± 0.2 ℃.The temperature control accuracy of the constant temperature system is ± 0.1 ℃,and the temperature uniformity is ± 0.1 ℃.The two systems were validated by biological experiments,and the electrophoresis results showed that the electrophoresis band width and size met the requirements.Provide ideas and laboratory technology for the subsequent development of nucleic acid amplification technology and nucleic acid hybridization technology temperature control systems.