In this paper, a prototype of a semi-automatic lab-on-PCB for agarose gel preparation and electrophoresis is developed. The dimensions of the device are 38 × 34 mm${}^2$ and it includes a conductivity sensor for detecting the TAE buffer (Tris-acetate-EDTA buffer), a microheater for increasing the solubility of the agarose, a negative temperature coefficient (NTC) thermistor for controlling the temperature, a light dependent resistor (LDR) sensor for measuring the transparency of the mixture, and two electrodes for performing the electrophoresis. The agarose preparation functions are governed by a microcontroller. The device requires a PMMA structure to define the wells of the agarose gel, and to release the electrodes from the agarose. The maximum voltage and current that the system requires are 40 V to perform the electrophoresis, and 1 A for activating the microheater. The chosen temperature for mixing is 80 ${}^{\circ }$C, with a mixing time of 10 min. In addition, the curing time is about 30 min. This device is intended to be integrated as a part of a larger lab-on-PCB system for DNA amplification and detection. However, it can be used to migrate DNA amplified in conventional thermocyclers. Moreover, the device can be modified for preparing larger agarose gels and performing electrophoresis.

中文翻译：

---

用于生物医学应用的琼脂糖凝胶制备和电泳的半自动 PCB 实验室系统

在本文中，开发了用于琼脂糖凝胶制备和电泳的半自动 PCB 实验室原型。设备尺寸为 38 × 34 mm${}^2$它包括一个用于检测 TAE 缓冲液（Tris-乙酸盐-EDTA 缓冲液）的电导率传感器、一个用于增加琼脂糖溶解度的微加热器、一个用于控制温度的负温度系数 (NTC) 热敏电阻、一个光敏电阻 (LDR)用于测量混合物透明度的传感器，以及用于执行电泳的两个电极。琼脂糖制备功能由微控制器控制。该装置需要 PMMA 结构来定义琼脂糖凝胶的孔，并从琼脂糖中释放电极。系统执行电泳所需的最大电压和电流为 40 V，激活微型加热器所需的最大电压和电流为 1 A。选择的混合温度为 80${}^{\circ }$C，混合时间为10分钟。此外，固化时间约为 30 分钟。该设备旨在集成为更大的 PCB 实验室系统的一部分，用于 DNA 扩增和检测。然而，它可用于迁移在传统热循环仪中扩增的 DNA。此外，该装置可以被修改以制备更大的琼脂糖凝胶和进行电泳。