Study on the Difference of Urine Sediment Preparation for Microscopic Examination

현미경검사를 위한 요침사 표본제작에 따른 차이 연구

  • Lee, Hyeok-Jae (Department of Biomedical Laboratory Science, Gwangju Health University) ;
  • Park, Chul (Department of Biomedical Laboratory Science, Gwangyang Health College) ;
  • Seo, Min-Young (Department of Biomedical Laboratory Science, Gwangju Health University)
  • 이혁재 (광주보건대학교 임상병리과) ;
  • 박철 (광양보건대학교 임상병리과) ;
  • 서민영 (광주보건대학교 임상병리과)
  • Received : 2017.10.18
  • Accepted : 2017.10.26
  • Published : 2017.12.31


Urinalysis is considered to be easier and simpler than other tests. It has been known to cause no burden to patients, while offering important information on diagnosing, treating, and determining the prognoses of kidney and urinary tract diseases. Urinary sediments are usually performed by microscopic examination of centrifuged urine by technologist. The guidelines proposed by the Korean Association of External Quality Assessment Service are actually different from those actually practiced by medical institutions and taught to biomedical students in textbooks. Therefore, we verified whether different sediment preparation methods lead different test results. Specimens that tested positive from the occult blood and leukocyte esterase in the urine dipstick test were randomly selected for a microscopic examination. The differences in the urine sediment preparation affected the sediment concentrations, which influenced the cell grade and cell number per HPF. The first factor in determining the sediment concentration is the centrifugal force. Many medical institutions use 1,500 rpm as the centrifugal speed without considering the radius of the centrifuge; such a value may not be accurate for 400 G. Consequently, there were differences in urine concentrations, which influenced the results. The second factor is the amount of sediment in urine. Different amounts of the remaining supernatant led to different sediment concentration factors, again, causing different results. Furthermore, not only by using a pipette to obtain an accurate amount as stipulated, but also by roughly obtaining a drop, the microscopic examination using such a volume of sediment examined affected the results. Therefore, this study highlights the importance of standardization of urine sediment preparation procedures to promote consistency and accuracy across institutions.


Supported by : Gwangju Health University


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