Urine
4.0 mL
Specimen Type: Clean-catch midstream (CCMS) or straight catheter urine is preferred to minimize contamination.
Volume: Ensure sufficient volume in both tubes (e.g., fill gray-top tube to the minimum line and the yellow-top tube not above the blue line).
Storage/Transport Temperature:
Preserved Tubes (Yellow-top and Gray-top): Stable at room temperature for up to 72 hours (yellow-top) or 48 hours (gray-top).
Unpreserved Urine in a Sterile Cup (if tubes not available): Must be refrigerated immediately and delivered to the lab within 2 hours of collection for processing.
(RML)
Interference
Contamination: Improper clean-catch technique can lead to contamination with normal flora from the skin, rectum, or vagina, potentially causing false-positive culture or PCR results.
Delay in Processing: Unpreserved urine left at room temperature for more than 2 hours can result in bacterial overgrowth, leading to inaccurate results.
Preservative Issues:
**Tubes containing the incorrect preservative (e.g., tubes with tartaric acid) are generally unacceptable.
**Do not submit low-volume specimens in underfilled gray-top tubes, as this affects the preservative-to-urine ratio.
Medications/Diet: Certain medications, vitamins, and food products may interfere with specific chemical assays on the dipstick (e.g., low pH or high glucose in urine can cause false-negative nitrite results).
Visible Particles: Large visible particles in the urine can lead to specimen rejection.
Miscellaneous Instruction to Collector
Patient Instructions: Provide clear, detailed instructions for a proper clean-catch midstream collection to the patient.
PPE: Use appropriate personal protective equipment (PPE), such as gloves, during the collection and transfer process.
Labeling: Label all containers with the patient’s full name, date, actual time of collection, and collection method (e.g., clean-catch, catheterized).
Transfer Process: If collecting in an initial sterile cup, transfer the urine into the appropriate transport tubes within 10 minutes using the designed transfer device.
Foley Catheters: Do not collect urine from an existing indwelling catheter drainage bag; collect a fresh specimen from the catheter itself using a sterile needle and syringe after cleaning the port, or via an in-and-out catheterization.
81003
