Department of BioNano Technology, Gachon University, 1342 Seongnam-daero, Sujeong-gu, Seongnam-si, Gyeonggi-do 13120, Korea.
Lab Chip. 2019 Apr 9;19(8):1397-1405. doi: 10.1039/c8lc01389f.
In this study, we have developed a foldable microdevice fully integrating DNA purification, amplification, and detection processes for detecting multiple foodborne pathogens. Specifically, the loop-mediated isothermal amplification (LAMP) technique was combined with a fuchsin-based direct DNA colorimetric detection method. The microdevice was composed of three parts: a sample zone, reaction zone, and detection zone. A sealing film attached to the sample, reaction, and detection zones served as a bottom layer to make the microdevice foldable. The detection zone was made up of paper strips attached to the sticky side of the sealing film, and fuchsin-stained lines were drawn on the paper strips. The microdevice can be folded to directly transfer the DNA template solution from the sample chambers to the reaction chambers. In this manner, fluid manipulation was readily realized and the use of a bulky instrument such as a pump or rotator was completely dispensed with. After the LAMP reaction, the detection zone was folded so that the fuchsin-stained lines were completely soaked into the reaction chambers. Genomic DNAs of Salmonella spp. and Escherichia coli O157:H7 were first successfully purified from thermally-lysed milk using polydopamine-coated paper, amplified by LAMP, and directly identified by the naked eye using fuchsin within 65 min. Using this microdevice, approximately 102 CFU per mL of Salmonella spp. was detected. These results indicate the significant potential of this microdevice for the sample-in-answer-out genetic analysis of multiple foodborne pathogens in resource-limited environments.
在本研究中，我们开发了一种可折叠的微器件，可完全整合 DNA 纯化、扩增和检测过程，用于检测多种食源性病原体。具体而言，环介导等温扩增（LAMP）技术与基于甲酚红的直接 DNA 比色检测方法相结合。该微器件由三个部分组成：样品区、反应区和检测区。附着在样品、反应和检测区的密封膜作为底层，使微器件可折叠。检测区由附着在密封膜粘性侧的纸条组成，并在纸条上绘制甲酚红染色线。微器件可以折叠，将 DNA 模板溶液直接从样品腔转移到反应腔。这样，很容易实现流体操作，完全不需要使用泵或旋转器等大型仪器。在 LAMP 反应后，将检测区折叠，使甲酚红染色线完全浸入反应腔。首先，使用多巴胺涂层纸从热裂解牛奶中成功纯化了沙门氏菌和大肠杆菌 O157:H7 的基因组 DNA，通过 LAMP 进行扩增，并通过甲酚红在 65 分钟内直接用肉眼进行鉴定。使用这种微器件，可检测到约 102 CFU/mL 的沙门氏菌。这些结果表明，该微器件在资源有限的环境中用于多种食源性病原体的样本到答案的遗传分析具有重要的潜力。
