Microscopic Examination of Urine - Introduction Flashcards
Microscopic examination must include
Both identification and quantitation
Purpose of microscopic urine examination
To detect and to identify insoluble materials
Microscopic analysis is subject to several procedural variations, including
Methods of sediment preparation
Volume of sediment examined
Methods and equipment used
Manner reporting results
First procedure to standardize the quantitation of formed elements
Addis Count
Specimen for microscopic examination
12-hour specimen
Normal Addis count value for RBC
0-500,000 cells /µL
Normal Addis count value for WBC and epithelial cells
0-1,800,000 cells /µL
Normal Addis count value for hyaline cast
0-5000 cells/µL
Specimen for microscopic examination must be
Fresh or preserved
A standard amount of urine to be centrifuged
Usually between 10-15 mL; 12-mL volume is frequently used
Ideal speed and time of centrifugation
5 minutes at RCF of 400
Amount of post-centrifuged specimen
0.5-1.0 mL
How to maintain a uniform sediment concentration factor?
Urine should be aspirated off rather than poured off
How to provide equal distribution of elements in the microscopic examination fields?
Thorough resuspension is essential
Volume of sediment to be examined
20 µL/0.02 mL
Commercial system designed such that after centrifugation, it can be decanted with a quick smooth motion and consistently retains 0.4 mL of urine for sediment resuspension
UriSystem
Commercial system that uses a specially designed pipette that snuggly fits the diameter and shape of the tube to retain 1 mL of urine during decanting
KOVA System
Commercial system that offers several options to retain 0.8 mL for sediment resuspension
Count-10 System
Commercial system that provides a specially designed tube that permits direct reading of the urine sediment
Cen-Slide 2000 Urinalysis System
Commercial system consists of a glass flow cell into which urine sediment is pumped, microscopically examined, and then flushed from the system
R/S Workstations
How to observe urinary sediments?
Observation of a minimum of 10 fields under both low (10X) and high (40X) power
Location for casts detection
Edge of the slide
Objective used to detect casts and ascertain general composition of sediment
Low power
Objective used in identification of casts and sediments
High power
