The Revision Guide for Student Nurses (Part I)

Urine Examination (Dry Prep) - Practical Task

INTRODUCTION
The microscopic examination of urine may be extremely useful in aiding or confirming a diagnosis. The dry preparation technique is the method of choice for the identification of cells and bacteria.

EQUIPMENT

  • Protective apron and gloves.
  • Fresh urine sample.
  • Centrifuge tubes.
  • Pasteur pipette.
  • Centrifuge.
  • Microscope slides.
  • Pencil to label slides.
  • Sink and drainer.
  • Leishman's stain.
  • Buffered distilled water.
  • Microscope.

METHOD

  1. Put on your protective apron and gloves, ensure that long hair is tied back and any jewellery removed.
  2. Ensure that you have a flat, clean, dry surface upon which to work.
  3. Check the microscope and centrifuge for safety - paying particular attention to the plug and electrical cable.
  4. Ensure that the urine sample is in a clean, tightly sealed container, then shake to re-suspend any deposits.
  5. Pipette urine into 2 centrifuge tubes, filling them to about two thirds full. (2 tubes are required in order to balance the centrifuge, although water may be used for one if there is only a very small sample available to test).
  6. Spin the urine at 2000rpm for 5 minutes.
  7. Remove most of the supernatant carefully with a pipette (pouring off the supernatant may be easier, but take care not to dislodge the sediment).
  8. Flick the base of the tube to re-suspend deposits.
  9. Label the microscope slide/s.
  10. Pipette 1 drop of urine onto the slide and make a smear.
  11. Air dry.
  12. Place the slide on a suitable rack or drainer over the sink and flood with Leishman's stain; wait 2 minutes.
  13. Add twice the volume of buffered distilled water and mix carefully without disturbing the actual smear.
  14. Let stand for 15 minutes until a metallic scum appears.
  15. Wash the slide with distilled water.
  16. Air dry.
  17. Switch on the microscope and examine under low power to scan the field.
  18. Select the oil immersion objective to examine for epithelial cells, leukocytes, erythrocytes and bacteria.