In the part "Procedures used in urinary sediment analysis" you will find out to what careful attention should be paid by analyzing urinary sediment (preanalytical, analytical, and postanalytical steps). So you will be enabled to avoid errors that may appear in your work.

Simple first-step urinalysis includes physical, chemical and microscopic examination of the urine. Urinary sediment microscopy is a method of long tradition, however, it has not yet been completely standardized. It includes the following:

 sediment preparation (urine specimen volume, sediment separation, sediment volume),
 real volume of sediment analyzed,
 methods of visualization,
 instruments used, and
 mode of issuing results.

Standardization of urinary sediment microscopic examination can be divided into standardization of the:

 preanalytical step,
 analytical step, and
 postanalytical step.

  Preanalytical step

Preanalytical step includes: specimen collected, urine specimen storage and standardization of urinary sediment preparation
Only fresh urine is used for microscopic examination of urinary sediment
Procedure of standardized specimen preparation includes:

 specimen volume standardization,
 procedure with turbid urine specimens,
 centrifugation,
 factor of sediment concentration, and
 urinary sediment staining.

There are a number of methods for urinary sediment staining. Only three methods are diagnostically valuable and widely used:

 staining according to Sternheimer-Malbin,
 staining according to Sternheimer, and
 staining according to Kaye, modified by Lampen (peroxidase staining).

 Analytical step

Analytical step includes: microscopic examination
Microscopic examination of urinary sediment has a diagnostic value considering the presence of cellular elements, casts and microorganisms in the urine.

Optical instruments used for urinary sediment examination are:

 light microscope,
 darkfield microscope,
 phase-contrast microscope,
 interference microscope, and
 fluorescence microscope.

 Postanalytical step

Postanalytical step includes the finding of urinary sediment microscopy
The finding of urinary sediment microscopy is issued in a descriptive form. The elements found must be listed, and their amount approximately expressed. The composition of the organized portion of urinary sediment usually is written first, followed by the non-organized part.
Each specimen in which suspected or atypical epithelial cells have been observed should be referred for additional cytologic analysis. The results of microscopic examination should be correlated with the physicochemical findings of the urine.