Automation of routine urinalysis, including microscopic analysis, is becoming more commonplace in clinical laboratories. Among the advantages of automation are faster turnaround time and standardization of sediment findings. Automated systems improve standardization by eliminating potential variability between testing personnel during slide preparation and interpretation.
However, laboratories may still need to perform manual urine sediment examinations when laboratory-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 criteria 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 particles. 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 automated findings.
Urine sediment contains all the formed elements or insoluble materials that have 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. In some cases, the images are enhanced by the use of various stains or through the use of other microscopic techniques, such as polarized light or phase-contrast microscopy.