Dynamic high-resolution full-field optical coherence microscopy of living mouse oocytes and early embryos for label-free assessment of development potential

Accurate, non-invasive assessment of oocyte and embryo quality is essential for advancing reproductive biology and improving assisted reproductive technologies (ART). We present a high-resolution full-field optical coherence microscopy (FF-OCM) system that enables label-free imaging of live mouse oocytes and preimplantation embryos. The system is integrated into a commercial fluorescence microscope for multimodal imaging and achieves optical sectioning with lateral/axial resolution of 0.5/1.2µm using low-intensity broadband visible light. FF-OCM resolves fine intracellular structures such as chromatin, nucleoli, meiotic spindles, cortical actin, and transzonal projections. Beyond static morphology, the system captures dynamic intracellular processes such as cytoplasmic streaming, nuclear envelope fluctuations, and nucleolar motion—processes driven by the actomyosin cytoskeleton and closely associated with developmental potential. This non-invasive, time-resolved modality offers new opportunities for improving embryo evaluation and advancing our understanding of early developmental processes.