Routine urinalysis, including microscopic analysis, is becoming more commonplace in clinical laboratories. Automation offers advantages such as faster turnaround time and standardization of sediment findings. Automated systems improve standardization by eliminating potential variability between testing personnel during slide preparation and interpretation.
Laboratory scientists and technicians may still need to perform manual urine sediment examinations when established criteria are met. In a laboratory where urinalysis is not fully automated, criteria for manual sediment examination may be based on the results of the reagent strip test. In a laboratory where urinalysis is fully automated, the requirements may be based on results obtained from the automated microscopic evaluation. Automated systems that are currently available use different technologies to classify and quantify urine-formed elements. Each system has certain classes of particles that are not positively identified by the automated system and, therefore, require manual microscopic examination of the sediment to confirm computerized findings.
Urine sediment contains all the formed elements or insoluble materials accumulated in the urine through its passage from the kidney to the lower urinary tract. These formed elements include cells, casts, crystals, and miscellaneous structures. This course will cover cellular and non-cellular findings in urine sediment. Images are provided to assist the learner with recognition of the particles when a wet mount of urine sediment is examined using brightfield microscopy. The photos are sometimes enhanced using various stains or microscopic techniques, such as polarized light or phase-contrast microscopy.