Autofluorescence image of a human kidney stone collected from a patient using percutaneous nephrolithotomy (PCNL) under sterile operating room conditions at the Mayo Clinic in Rochester, Minnesota. The sample is comprised of a complex crystalline growth sequence of hydroxyapatite, calcium oxalate monohydrate, calcium oxalate dihydrate and uric acid. A 30 micron-thick polished slice of the kidney stone was imaged on a Zeiss LSM 880 Airyscan microscope. This tiled super-resolution image was obtained using three fluorescence channels, with excitation wavelengths of 488, 561 and 633 nm. Bright red fluorescence indicates areas where epoxy fills void spaces, while all other emissions are caused by emissions from organic material entombed within the kidney stone crystals. This image indicates that several unexpected events took place during the formation of the kidney stone, which include: (1) multiple events of wholesale mineral dissolution and recrystallization; (2) mobilization and re-assembly of multiple stone fragments; (3) ultra nanometer-scale layering; and (4) entombment and preservation of microbial biofilms.
