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Abstract: SA-PO1032

Preservation of Slides of Fixed Urinary Sediment for Educational Purposes

Session Information

Category: Pathology and Lab Medicine

  • 1800 Pathology and Lab Medicine


  • Cohen, Lauren, Ochsner Health, New Orleans, Louisiana, United States
  • Velez, Juan Carlos Q., Ochsner Health, New Orleans, Louisiana, United States
  • Seltzer, Jay R., Missouri Baptist Medical Center, Saint Louis, Missouri, United States

Urine sediment slides for microscopy are best inspected promptly, as drying artifact, the result of evaporation, will occur and limit the time the slide is viable for viewing. Although teaching urine microscopy using stored images of cells, casts, and crystals is useful, there is no replacement for real-time microscopic examination of a urine sediment slide. Thus, we aimed to develop a reproducible method of preserving urine sediment slides.


Urine specimens from patients at Ochsner Medical Center (New Orleans) and Missouri Baptist Medical Center (St Louis) seen by the nephrology department were randomly chosen based on the presence of distinct urine sediment findings. Specimens were centrifuged and the supernatant discarded. Ten drops of 10% buffered formalin were added to resuspended pellets. After 30 minutes, samples were centrifuged for 2 minutes and remaining supernatant was discarded. The new pellet was resuspended in a solution of 1 drop of Sternheimer-Malbin stain, 2 drops of glycerol, and 1 drop of clear Elmer’s® glue. One drop of this mixture was placed on the slide and a coverglass applied. CoverGrip® was painted around the perimeter of the coverglass as a sealant. Slides were examined at regular intervals (24, 48, 96 hours; 1, 2, 4, 8 weeks) and images were captured using SeBaCam®. Slide quality was evaluated for structure retention, stain intensity, and evaporation artifact.


Various cast types (granular, waxy, cellular, vacuolated), acanthocytes, and crystals were captured in the preserved slides across all specimens (n = 12). The integrity of the structures identified on day 1 was preserved up to 8 weeks in all cases. No significant decay in quality was observed over time. Artifacts observed included evaporation artifact, cloudiness, and stain fading. However, none of those factors altered the overall interpretation of the slide. A library of preserved slides was successfully used by the authors in a recent hands-on educational workshop (KidneyCon).


Our novel method of urine sediment slide preservation was effective in preserving the quality and quantity of the findings revealed upon inspection immediately following urine collection. This technique can be implemented in academic centers for educational and clinical purposes. Further studies are required for optimization.