Temporally resolved assays of bacterial gene expression using printed fluorescence imaging boxes (PFIboxes) are non-destructive, inexpensive and simple to prepare. Herein, we describe a full experimental pipeline wherein PFIbox parts are modified and 3D printed, electronics assembled and used to study transcriptional responses of Escherichia coli to chemical stressors. A chemical probe is added to agar growth medium, and a promoter–fluorophore fusion library is arrayed in high density on the agar slab. With high temporal resolution, the reporter library is imaged in PFIboxes, then quantified using promoter activity as a measure of gene expression. PFIboxes have advantages over conventional transcriptomic approaches such as RNA-seq, as the non-destructive nature permits a high-resolution temporal dimension in the data. This results in rapid measurement of transcriptional responses to chemical or physical stimuli. Each time-course gene expression assay costs about US$2 to run, in triplicate, using this method. Printing time depends on printer and settings, but once printed, PFIboxes can be fully assembled, programmed and loaded with samples in less than 1 h. Experimental durations and sampling frequency are set according to user need, but can be run in the duration of a microbial growth curve.

使用印刷荧光成像盒 (PFIbox) 对细菌基因表达进行时间分辨分析是非破坏性的、价格低廉且易于制备。在这里，我们描述了一个完整的实验管道，其中 PFIbox 部件被修改和 3D 打印，电子组装并用于研究大肠杆菌的转录反应对化学压力源。将化学探针添加到琼脂生长培养基中，启动子-荧光团融合文库以高密度排列在琼脂板上。具有高时间分辨率，报告文库在 PFIboxes 中成像，然后使用启动子活性作为基因表达的量度进行量化。PFIboxes 比 RNA-seq 等传统转录组学方法具有优势，因为其非破坏性特性允许数据中的高分辨率时间维度。这导致对化学或物理刺激的转录反应的快速测量。使用这种方法，每个时间进程基因表达分析的运行成本约为 2 美元，一式三份。打印时间取决于打印机和设置，但打印后，PFIbox 可以在不到 1 小时内完全组装、编程和加载样品。