Microscopic Examination of Urine Part I - UNMC

MicroscopicExamination ofUrinePart IObjectives:• Review the objectives on page 1 and 2 ofthe lecture handout• Objectives marked with ‘*’ will not betested over during student lab rotationRicki Otten MT(ASCP)SCuotten@unmc.eduStandardization of Microscopic Exam• Strict adherence to laboratory protocolusing the same:– Supplies– Sequence of procedural steps– Timing intervals– Equipment• Ensures accuracy and precision ofmicroscopic analysis of urine sedimentCommercial Systems• Produce the same concentration of urineor sediment volume• Present the same volume of sediment formicroscopic analysis• Control microscopic variables such asfocal planes and optical properties ofslidesCommercialSystemsKOVA slide system7 Factors to Standardize1. Specimen collection and handling2. Specimen volume3. Centrifugation4. Sediment concentration5. Volume of sediment examined6. Consistent examination procedure7. Reporting format and terminology1

1. Proper Specimen• Collection– Patient prep may or may not be done– Random, clean catch, catheterized, etc• Rapid transport to lab– Room temperature,refrigerated specimen2. Volume of urine evaluated• Well- mixed urine• 12 milliliters (10- 15 mL range) routinevolume analyzed• Prompt examination– Within 30 minutes ofcollection ideal2. Volume of urine evaluated• Notation must accompany report on all volumesanalyzed that are not routine (12 ml volume)– 6 mL (all numerical counts doubled, always followlaboratory protocol)–

CommercialSystems6. Consistent examination• Minimum ‘10 representative fields’Example:KOVA slide system• Elements must be evenly distributedthroughout slide•• If not, prepare another wet prep• What is a Field of View (FOV)?Field of View (FOV)Field of View (FOV)FOV: what you see through the ocular lensLow Power Objective• 10x objective• Examine perimeter of cover-slip• Look for– Squamous epithelial cells– Casts– MucusField # 1Field # 23

Scanning the Microscope Slide• Use 10X objective: scan the coverslip perimeterfor squamous epithelial cells, cast and mucus• Example: begin in the upper right hand corner,down the right side then the bottom, up and over• Remember to scan a MINIMUM of 10 FIELDSHigh Power Objective• 40x objective• Examine center area of cover-slip• Look for– RBC and WBC– Transitional and renal tubular epithelialcells–Bacteria– Yeast– Sperm– Trichomonads– CrystalsScanning the Microscope Slide• Use 40X objective, scan the interior of the slide• Look for all other cellular elements• Remember to scan a MINIMUM of 10 FIELDS7. Report format and terminology• Number per low power field:– 20- 100 squamous epithelial cells/lpf– 0- 3hyaline casts/lpf– 5- 10 granular casts/lpf• Number per high power field:– 10- 25 RBC/hpf– 5- 10 renal tubular epithelial cells/hpfEnsure Accuracy in ReportingMicroscopic results should be correlated to thephysical and chemical resultsTechniques Used to EnhanceVisualization•Stains• Microscopic techniques4

Fat Stains: Sudan III, Oil Red OStain fats characteristic orange- red colorAcetic Acid, 2%• Enhances nuclear structure of WBC• Differentiates RBC from yeast (RBC will hemolyze)Microscopic TechniquesMicroscopic Techniques5