Abstract:

Bioanalytical technology is being developed towards the direction of high throughput, high sensitivity and multi-functionality. Microplate readers serve as fundamental instruments for high-throughput analysis. They need to meet the requirements of microanalysis, automation and integration. At present, domestic instruments have limitations in terms of functionality and automation. Although the single-function microplate reader has basically reached the level of oversea equivalents, there is still a gap in the multifunctional instruments. Most of the multi-function microplate reader used are imported instruments. They are usually expensive and some operating instructions are not fully disclosed. It is difficult to integrate them into the automated foundry platform. In this study, we will research key technologies of high-precision absorbance detection and high-sensitivity fluorescence detection, and develop a multifunction microplate reader. The control and soft system is also developed independently to access the automated foundry platform. In our system, the absorbance optical system includes light source, filters, fibers and lens array. Multiple channels of transmitted light are detected in parallel to improve the speed of detection. Combined with the one-dimensional movement of microplate, the whole 96 wells are measured. The fluorescence optical system mainly includes LED light source, filter cube (emission filter, excitation filter and dichroic mirror) and photodiode detector. Single channel of excitation light is detected and two-dimension scanning mechanism is realized for the whole microplate measurement. Besides the optical system, high precision data acquisition system is developed, including signal amplifying, conditioning and isolating circuit. This microplate reader is compact with independent absorbance and fluorescence modules, and scalable wavebands. According to experimental results, the reproducibility of absorbance measurement is high with a standard error of 0.3% and the total 96 micro-wells can be detected accurately within 10 seconds. The fluorescence detection has good linearity in the picomole concentration and the limit of detection for sodium fluorescein is about 3.9 pmol/L. For synthetic biology automated foundry platform, this microplate reader can be directly connected to the integration control system through serial port, and can also be remotely controlled by TCP communication.

Key words: microplate, automation platform, optical density, fluorescence detection

摘要：

生物分析技术正向高通量、高灵敏度、多功能方向发展，微孔板检测仪作为高通量分析的基础仪器，需要满足微量化、自动化、集成化的要求。目前国内单一功能的微孔板检测仪器技术成熟，检测精度已与国际水平相当，但多功能的微孔板检测仪还较少，大多使用进口仪器。进口产品价格昂贵，有些操作指令不公开，不易集成到自主研发的合成生物自动化铸造平台项目。本研究将对高精度吸光度检测和高灵敏度荧光检测等关键技术进行研究，开发具有吸光检测和荧光检测功能的微孔板检测仪，并自主开发控制系统及数据采集分析软件，使其易于接入自动化铸造平台。该微孔板检测仪结构紧凑，吸光检测和荧光检测模块独立，波段可扩展。通过实验测试，所研发的微孔板检测仪的吸光度检测重复性为0.3%，10 s内可完成96孔的吸光检测；荧光检测数据在皮摩尔浓度范围内线性度较好，对荧光素钠溶液的检测灵敏度大约3.9 pmol/L。此外，该系统可通过串口直接连接自动化平台集成控制系统，也可通过TCP方式进行远程通信控制。

关键词: 微孔板, 自动化平台, 吸光度, 荧光检测