Cryo-X-ray Phase Contrast Imaging enables combined 3D structural quantification and nucleic acid analysis of myocardial biopsies

Snap frozen biopsies serve as a valuable clinical resource of archival material for disease research, as they enable a comprehensive array of downstream analyses to be performed, including extraction and sequencing of nucleic acids. Obtaining three-dimensional (3D) structural information prior to multi-omics is more challenging but could potentially allow for better characterisation of tissues and targeting of clinically relevant cells. Conventional histological techniques are limited in this regard due to their destructive nature and the reconstruction artifacts produced by sectioning, dehydration, and chemical processing. These limitations are particularly notable in soft tissues such as the heart. In this study, we assessed the feasibility of using synchrotron-based cryo-X-ray phase contrast imaging (cryo-X-PCI) of snap frozen myocardial biopsies and 3D structure tensor analysis of aggregated myocytes, followed by nucleic acid (DNA and RNA) extraction and analysis. We show that optimal sample preparation is the key driver for successful structural and nucleic acid preservation which is unaffected by the process of cryo-X-PCI. We propose that cryo-X-PCI has clinical value for 3D tissue analysis of cardiac and potentially non-cardiac soft tissue biopsies prior to nucleic acid investigation.