Dynamic full-field optical coherence tomography module adapted to commercial microscopes allows longitudinal in vitro cell culture study

Dynamic full-field optical coherence tomography (D-FFOCT) has recently emerged as a label-free imaging tool, capable of resolving cell types and organelles within 3D live samples, whilst monitoring their activity at tens of milliseconds resolution. Here, a D-FFOCT module design is presented which can be coupled to a commercial microscope with a stage top incubator, allowing non-invasive label-free longitudinal imaging over periods of minutes to weeks on the same sample. Long term volumetric imaging on human induced pluripotent stem cell-derived retinal organoids is demonstrated, highlighting tissue and cell organization processes such as rosette formation and mitosis as well as cell shape and motility. Imaging on retinal explants highlights single 3D cone and rod structures. An optimal workflow for data acquisition, postprocessing and saving is demonstrated, resulting in a time gain factor of 10 compared to prior state of the art. Finally, a method to increase D-FFOCT signal-to-noise ratio is demonstrated, allowing rapid organoid screening. Dynamic full-field optical coherence tomography coupled to a commercial microscope with a stage top incubator, allows non-invasive, long term, label-free longitudinal imaging of biological specimens.

Automated summary

Dynamic full-field optical coherence tomography (D-FFOCT) is a label-free imaging tool that can distinguish cell types and organelles in 3D live samples and monitor their activity. In this study, a D-FFOCT module design is presented that can be coupled to a commercial microscope with a stage top incubator, allowing non-invasive longitudinal imaging over extended periods of time. The imaging of human induced pluripotent stem cell-derived retinal organoids and retinal explants demonstrates the capability of D-FFOCT in capturing tissue and cell organization processes as well as individual structures. The optimized workflow for data acquisition, postprocessing, and saving significantly improves the efficiency compared to previous methods. Additionally, a method to increase the signal-to-noise ratio of D-FFOCT is demonstrated, enabling rapid screening of organoids.