Collect aseptically into a sterile vial/tube
Ambient (preferred) - 14 days
Refrigerated - 14 days
Frozen - 14 days
Freeze/thaw cycles - stable x3
Enzymatic
Synovial fluid: 65 - 99 mg/dL
Amniotic fluid: 45 - 76 mg/dL
Decreased fluid glucose concentration is usually associated with septic or inflammatory processes; in pleural effusion, very low glucose is a facet of rheumatoid effusion: pleural fluid glucose <50 mg/dL characterizes rheumatoid effusion. It is often much less.
Potts et al describe loculated effusions or empyemas with low glucose and low pH. Low glucose is found with empyema, tuberculosis, neoplasia, and rheumatoid effusion. In cases of malignant pleural effusions, when there is low pleural fluid glucose (<60 mg/dL) and pH <7.30, a probability of 90% that the cytologic yield will be positive was reported.