Sysmex Journal International

2014Vol.24 No.1


Field Volume of Urine Sediment Test ー Comparison of Theoretical Volume with Practical Volume



Central Laboratory, Gifu Municipal Hospital


The guideline for hematuria diagnosis was disclosed in March 2006. It has been defined as diagnostic criteria for hematuria that 5 or more red blood cells/HPF( high-power field, × 400 ) in the urinary sediment sample under microscopy and/or 20 or more red blood cells/μL by using flow cytometry technique with non-centrifuged urine sample are detected.

One HPF of microscopy for urinary sediment is theoretically equivalent to 0.45μL of non-centrifuged urine sample. However, in fact, there is discrepancy between theory and practice for some reasons. In this study, we examined the variance using KOVA slide.

We counted the urinary formed elements of primitive urine and urinary sediment. The results showed the tendency for the small elements to have greater discrepancy than large elements between theory and practice. It might well suggest that the small elements are easy to remain in the supernatant and to be adsorbed to the tube wall through a centrifugal process.

In our results, one HPF of microscopy for urinary sediment was equivalent to 0.31μL for squamous epithelial cells, 0.20μL for white blood cells, and 0.20μL for red blood cells.

This result meets the proportion of 20RBC/μL of primitive urine to 5RBC/HPF under microscopy in the diagnostic criteria for hematuria.


Non-Centrifugal Urine, Urine Sediment, Field Volume, KOVA Slide, SEKISUI Plate


This article is translated and republished from the Sysmex Journal Web Vol. 8 No. 2, 2007. (Japanese)