INTRODUCTION
The microscopic examination of urine may be extremely useful in aiding or confirming a diagnosis. The wet preparation technique is a quick and simple method ideal for the identification of crystals, casts and mucus strands.

EQUIPMENT

• Protective apron and gloves.
• Fresh urine sample.
• Centrifuge tubes.
• Pasteur pipette.
• Centrifuge.
• Sedistain (optional).
• Microscope slides.
• Pencil to label slides.
• Cover slips.
• Microscope.

METHOD

1. Put on your protective apron and gloves, and 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, and shake to re-suspend any deposits.
5. Pipette urine into 2 centrifuge tubes, filling them 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. Add 1-2 drops of Sedistain if required.
9. Shake vigorously - again to re-suspend the deposits.
10. Label the microscope slide/s.
11. Pipette 1 drop of the suspension onto the slide.
12. Place a cover slip onto the slide.
13. Switch on the microscope and select the x10 objective, a fairly dim illumination improves visualisation (ensure that the condenser is down and the iris diaphragm partially closed.
14. Select the x40 objective; note the presence of any crystals, casts or strands.