Collection methods and criteria
Collection of split samples in sealed tamper-resistant containers
Direct observation of specimen collection (when required)
Sample size of 30 mL or more
Temperature between 90°F (32.2°C) and 100°F (37.7°C)
Urine pH of 4.5 to 8.5
Use of an approved chain of custody form to track specimen handling
Findings suggestive of adulterated, diluted, or substituted specimens*
General
	Temperature < 90°F or > 100°F
	Unusual appearance (e.g., bubbly, cloudy, clear, dark)
Adulterated
	Nitrite concentration >5 00 mg per dL (4.2 mmol per L)
	Urine pH < 3 or ≥ 11
Diluted
	Creatinine concentration ≥ 2.0 mg per dL but < 20 mg per dL (176.8 mmol per L)
	Specific gravity > 1.0010 but < 1.0030
Substituted
	Creatinine concentration < 2.0 mg per dL (17.68 mmol per L)
	Specific gravity ≤ 1.0010 or ≥ 1.0200