P. M. W. French

‘ openFrame ’ is a modular, low‐cost, open‐hardware microscopy platform that can be configured or adapted to most light microscopy techniques and is easily upgradeable or expandable to multiple modalities. The ability to freely mix and interchange both open‐source and proprietary hardware components or software enables low‐cost, yet research‐grade instruments to be assembled and maintained. It also enables rapid prototyping of advanced or novel microscope systems. For long‐term time‐lapse image data acquisition, slide‐scanning or high content analysis, we have developed a novel optical autofocus incorporating orthogonal cylindrical optics to provide robust single‐shot closed‐loop focus lock, which we have demonstrated to accommodate defocus up to ±37 μm with <200 nm accuracy, and a two‐step autofocus mode which we have shown can operate with defocus up to ±68 μm. We have used this to implement automated single molecule localisation microscopy (SMLM) in a relatively low‐cost openFrame ‐based instrument using multimode diode lasers for excitation and cooled CMOS cameras.

A single‐shot adaptation of Optical Projection Tomography (OPT) for high‐speed volumetric snapshot imaging of dynamic mesoscopic biological samples is presented. Conventional OPT has been applied to in vivo imaging of animal models such as D. rerio , but the sequential acquisition of projection images typically requires samples to be immobilized during the acquisition. A proof‐of‐principle system capable of single‐shot tomography of a ~1 mm 3 volume is presented, demonstrating camera‐limited rates of up to 62.5 volumes/s, which has been applied to 3D imaging of a freely swimming zebrafish embryo. This is achieved by recording eight projection views simultaneously on four low‐cost CMOS cameras. With no stage required to rotate the sample, this single‐shot OPT system can be implemented with a component cost of under £5000. The system design can be adapted to different sized fields of view and may be applied to a broad range of dynamic samples, including high throughput flow cytometry applied to model organisms and fluid dynamics studies.