Joint fluid



Birefringent crytals of uric acid in joint fluid

  • All joint aspirates are routinely examined microscopically for urate and calcium pyrophosphate crystals 
  • TB culture will be performed on request
  • Fluids taken as part of a prosthetic joint set are treated differently – see Prosthetic joint/bone samples

Sample requirements

30mL sterile Universal

A minimum of 1 mL is required, but a larger volume is desirable if possible

30 mL sterile Universal

Required information

  • Relevant clinical details
  • Recent, current and intended antibiotics


Samples should be transported to the laboratory with minimal delay.  Refrigerate samples if transport is delayed.

Turnaround time

Microscopy results on day of receipt

Culture results 2 – 3 days

Page last reviewed: 19/05/2014