Urine collection

Many urine chemistry tests require a 24-hour collection. Record on the test request form any medications that the patient is receiving. If a preservative is required, it is important that the designated preservative be in the urine collection container at the start of the collection. When the 24-hour urine output is less than 1 liter, 4 grams of boric acid can be used when boric acid is the specified preservative or 10 mL of 6N HCl can be used when HCl is specified. The patient (or responsible individual) should be cautioned that the preservative may be toxic and caustic, and not to spill or discard the preservative.

On the day of the collection, discard the first morning urine void, and begin the collection after this void. Collect all urine for the next 24 hours so that the morning urine void on the second day is the final collection. Measure and record this volume on the test request form and on the urine transport vial (see Pediatric Specimen Tubes below). Transfer the requested volume into the labeled urine transport vial. Do not send the entire urine collection.

Random urine

The normal composition of urine varies considerably during a 24-hour period. Most reference values are based on analysis of the first morning voided urine. This specimen is preferred because it has a more uniform volume and concentration, and its lower pH helps preserve the formed elements.

To reduce contamination, the specimen submitted for urinalysis should be a clean catch “mid-stream” sample.

Submit a first morning voided specimen whenever possible. Urine for pregnancy testing should be first morning void, or a random specimen with a specific gravity of at least 1.010. Note the time of collection of the specimen on the test requisition and on the label of the container. For urine chemistry tests, the 24-hour urine collection is the usual standard. For some of these tests, there are dietary restrictions that must be observed. For others, there are drug that must be avoided prior to obtaining the specimen. This information is included as part of the specimen requirements for the individual tests in the General Test Listing section.

Note: Specimens for Urinalysis must be submitted in a yellow/red swirl-top preservative tube. See Urinalysis test for specific information.

If a frozen specimen is required, freeze the urine immediately after collection. Pack in dry ice for transport to the laboratory. (See section on FROZEN SPECIMENS.)

Urine for culture

See Microbiology section for specific instructions.

24-hour urine

Because proper collection and preservation of 24-hour urine specimens are essential for accurate test results, patients should be carefully instructed in the correct procedure.

Important Note: For those analyses requiring the addition of 6N HCl, add the acid at the start of collection. Have the patient collect each voiding in a smaller container and carefully pour the urine into the 24-hour container to avoid any possible acid burns to the patient (make sure the patient understands the hazard presented by the acid preservative). Be sure to mix urine thoroughly before removing the aliquot.

Follow these instructions if someone other than the patient is to collect the urine:

1. Unless the physician indicates otherwise, instruct the patient to maintain the usual amount of liquid intake, but to avoid alcoholic beverages.
2. During the collection period, place the 24-hour urine container (with appropriate preservatives, if applicable) provided by Quest Diagnostics in a refrigerator or cool place to prevent growth of microorganisms and possible decomposition of urine constituents. (See specimen requirements for the individual tests in the General Test Listing section for any information on required preservatives.)
3. Have the patient empty his/her bladder in the morning into the toilet (not to be included in the 24-hour collection). Write the date and time of voiding on the container label.
4. Collect the patient’s next voiding and add it as soon as possible to the 24-hour container.
5. Add all subsequent voidings to the container as in (4). The last sample collected should be the first specimen voided the following morning at the same time as the previous morning’s first voiding.
6. Mix the contents of the container gently but thoroughly. Examine to ensure that the contents appear homogeneous.
7. Measure and note the total volume of urine.
8. Transfer the required aliquot to the plastic screw-cap plastic containers provided by Quest Diagnostics.
9. Record the total 24-hour urine volume on the specimen container and on the Test Requisition (Field 7 on the sample physician requisition) before sending to the laboratory.
10. If required, refrigerate the aliquot until it can be sent to the laboratory. For frozen specimens, freeze before packing in dry ice for transport. (See section on FROZEN SPECIMENS.)
11. Ensure the lid is properly tightened to prevent leakage.

Follow these instructions if the patient is to collect the urine:

Important Note: For those analyses requiring the addition of 6N HCl, add the acid to the 24-hour container at the start of collection. Have the patient collect each voiding in a smaller container and carefully pour the urine into the 24-hour container to avoid any possible acid burns to the patient (make sure the patient understands the hazard presented by the acid preservative). Be sure to mix urine thoroughly before removing the aliquot.

Give the patient the clean, labeled container provided by Quest Diagnostics, and instruct patient not to remove any preservatives (powder, liquid or tablet) that may be in the container. Alert the patient that preservatives are hazardous chemicals and are not to be ingested.

• Unless the physician indicates otherwise, instruct the patient to maintain the usual amount of liquid intake, but to avoid alcoholic beverages.
• Instruct the patient to carry out steps 3-5 above and return the 24-hour collection to your office for specimen pick-up.

Drug testing

Urine specimens for drug testing must be collected and submitted with no preservative.