Specimen Collection

Order of Draw

Vacutainer tubes must be drawn in a specific order to prevent carry-over contamination from the additives between tube changes during the collection.  The recommended short order of draw is:

• Blood Cultures
  • Blue – Aerobic
  • Purple - Anaerobic
• Blue tube (Coagulation)
• Gold Top w/gel, SST (Serum)
• Red Top (Serum)
• Light Green Top w/gel, PST (Plasma)
• Dark Green Top (Plasma)
• Lavender Top (EDTA)
• Pink Top (EDTA)
• Pearl Top (EDTA)
• Gray Top (Glycolytic inhibitor)

Note:  When using a winged blood collection set (Butterfly needle) for venipuncture and coagulation tube is the first tubed needed, first draw a blue discard tube.  The discard tube must be used to prime the tubing of the collection set, which will assure maintenance of the proper anticoagulant/blood ration in the first tube filled.  The discard tube should be a coagulation (blue top) tube, and need not be completely filled.

NOTE: Tubes with additives need to be gently inverted 8-10 times to thoroughly mix the blood sample with the additives.  Clotting or erroneous test results may be obtained when thorough mixing is not performed.

Labeling the sample

A specimen label must be legible and accurate so that the test results match the correct patient and must contain the following information:

• Patient’s full name
• Patient’s ID number (eg. MRN, DOB, accession number).  NOTE: Patient’s name and number MUST match the information on the test order.
• Date, time and collector I.D. must be on the label of EACH tube.

Centrifuging the sample

• Serum separator tubes should clot for 30 minutes before centrifugation or fibrin formation in the serum will occur.
• Centrifuge samples within a 2 hour time frame from collection to physically separate the cells from the serum or plasma.
• The gel barrier tubes are time, temperature and RPM dependent.  An incomplete barrier could occur if centrifugation times are shortened.  Gel flow may be impeded if the specimen is chilled before or after centrifugation.
• The centrifuge should be balanced when loaded.  Opposing tube holders should have identical tube volumes. 
• Generally, the spin time for a horizontally spun sample is 7 minutes.

24 Hour Urine Collection Instructions

A 24 hour urine collection is a timed test. All urine which is passed in a 24 hour

period is collected. The testing will not be accurate if the specimen is collected

improperly.

A 24-hour urine container is provided by the laboratory. For some tests, a preservative is required to be added to the container. This will be added by the laboratory, if applicable.

1. Urinate first thing in the morning. Do not save urine. Write down the time.
2. For the next 24 hours, collect all the urine that is passed after the first voiding and place in the jug provided.  Do not urinate directly into the container.  For example:  7:00 am was the first time the patient urinated for the day.  Write down 7:00 am and discard the urine.  Now collect all urine for the next 24 hours, including anything passed at 7:00 am the next morning (24 hours after the first voiding).  Urine passed during bowel movements must also be collected (but must not contain feces).    
3. All urine should be placed in the container provided.  If preservative is in the container provided, patient must not urinate directly into the container as splashing may occur.  Collect the specimen in a different clean container and pour into the jug provided.  If the chemical should spill out of the container, do not use it.  Obtain another container from the laboratory.
4. The chemical in the container may cause burns if touched. If ingested, a physician should be contacted immediately.
5. The entire specimen should be refrigerated at 2-8 C during collection, or kept in a cool place, since urine is an excellent culture medium for organisms and its components decompose quickly.
6. DO NOT add any more urine to the container after the 24-hour collection period.  To do so will cause inaccurate results.
7. Bring the urine to the laboratory as soon as possible once the collection is complete.  24-hour container must be properly labeled.  The collection times should be written on the 24-hour container.

Two Consecutive 24-Hour Urine Collections(One With Preservative And One Without Preservative)

FIRST 24-HOUR URINE COLLECTION

(PRESERVATIVE ADDED)

1. Urinate first thing in the morning. Do not save urine. Write down the time.
2. For the next 24 hours, collect all the urine that is passed after the first voiding and place in the jug provided.  Do not urinate directly into the container.  For example:  7:00 am was the first time the patient urinated for the day.  Write down 7:00 am and discard the urine.  Now collect all urine for the next 24 hours, including anything passed at 7:00 am the next morning (24 hours after the first voiding).  Urine passed during bowel movements must also be collected (but must not contain feces).

1. All urine should be placed in the container provided.

4. Patient must not urinate directly into the container as splashing may occur.  Collect the specimen in a different clean container and pour into the jug provided.  If the chemical should spill out of the container, do not use it.  Obtain another container from the laboratory.
5. The entire specimen should be refrigerated at 2-8 C during collection, or kept in a cool place, since urine is an excellent culture medium for organisms and its components decompose quickly.
6. The next morning patient should urinate upon awakening, but this time include the urine in the preservative container. Record date and time of this urination. Example: 1-1-2011, 7:30 A.M. This is the last sample to be included in the preservative container.
7. Bring the urine to the laboratory as soon as possible once the collection is complete.  24-hour container must be properly labeled.  The collection times should be written on the 24-hour container.

SECOND 24-HOUR URINE COLLECTION

(NO   PRESERVATIVE)

1. Record the date and time of the first urine of the day. The time is the same as the last entry of the preservative container.  (See #6 above)
2. From now on, all urine passed for the next 24-hour period must be included in the second container, with no preservative.  Urine passed during bowel movements must also be collected (but must not contain feces).  
3. Urine should be collected in another clean container and then carefully poured into the second container.
4. On the following morning, the first urine of the day must be included in this second container.  Record the date and time of this urination.  Example: 1-2-2011 7:30am.  This is the last sample to be included in the no preservative container.
5. Bring the urine to the laboratory as soon as possible once the collection is complete.  24-hour container must be properly labeled.  The collection times should be written on the 24-hour container.

CSF Specimen Requirements

The following guidelines should be used for specific laboratory tests from a spinal tap:

CSF Tube #1:

Chemistry/Serology Testing -

Although this specimen is most prone to blood contamination from a traumatic tap, it can be used for Chemistry and Serology testing with the understanding that some tests (i.e. proteins) are affected by this blood.  Tube #2 or #3 may also be used for Chemistry/ Serology tests in the absence of other tests.

CSF Tube #2:

Bacteriology Testing -

This specimen is preferable for Bacteriology testing over Tube #1 because contamination from skin flora is minimized. Tube #3 may be used in the absence of Hematology tests.

CSF Tube #3:

Hematology Testing -

This specimen is preferable for cell counts over Tubes #1 and #2 because the potential for false positive from a traumatic tap is minimized.

CSF Tube # 4:

Cytology-

If tube # 4 is not available Tube # 3 can be used for Cytology

REFERENCES:

Procedures for the Collection of Diagnostic Blood Specimens by Venipuncture; Approved Standard – Clinical and Laboratory Standards Institute, Sixth Edition, H3-A6, Vol. 27, No. 26, page 17.