Specimen Requirements for collection & handling
The quality of the information derived from a laboratory test depends greatly on the proper collection and handling of the specimen being submitted for analysis.
- Correct patient preparation
- Specimen collection
- Specimen packaging
Specimen requirements for each analysis, including sample size, are provided in alphabetical order on your fee schedule. To avoid inconvenience to the patient and the physician, please be sure to submit the specimen quantity specified for the test you wish to have performed. The requested volume is an amount sufficient to allow multiple runs if necessary. Before abnormal results can be given to the physician, it is necessary to repeat and verify the test result.
When insufficient specimens are submitted, your office will be contacted with a “QNS” (Quantity Not Sufficient) comment asking you to re-submit a sample for testing.
Please remember when filling the blood drawing tubes, most have measured amount of anticoagulant based on the size of the tube. The amount of anticoagulation is measured on the basis that the tube being submitted will be full.
As a rule of thumb, the volume of blood drawn should equal 2 times the amount of serum, or plasma required. For example, to obtain 4ml serum, draw at least 8ml blood.
For test(s) requiring plasma, thoroughly mix the blood in the proper anticoagulant tube by gently inverting the tube 5-10 times. If required, separate plasma from cells by centrifugation immediately after mixing. Carefully transfer the plasma, (yellowish colored liquid remaining on top of the red cells) by pipette to a plastic transport tube.
The order in which vacuum tubes are filled at the time of venipuncture is extremely important. The goal is to prevent the additives in one tube from contaminating the specimen in a subsequent tube. The recommended order of draw is as follows:
- Blood Cultures
- Non-Additive tube (Plain Red)
- Serum Separator (SST)
- Coagulation Tube (Blue)
For the test(s) requiring serum, draw blood into a serum separator tube (SST), this tube has a yellowish gel at the bottom. Allow blood to clot 10-15 minutes and separate by centrifugation for 15 minutes. DO NOT DRAW SERUM SAMPLES IN A PLAIN RED TOP TUBE WIHOUT GEL.
These tubes do not keep separation of the serum and cells of the blood; thus hemolysis could occur, which will greatly affect many test analysis. If a plain red tube top is used, separate serum from cells by centrifugation and transfer serum into a plastic transport tube.
Collect and transport in plastic, leak proof container(s) which are available from the laboratory.
24 Hour Urine (Get appropriate container from the Lab.)
For proper evaluation of tests on a 24-hour urine sample, it is important that a complete and accurate collection be made. Have a patient drink less liquids during the collection period, unless instructed otherwise by his/her physician. Patient must avoid any alcoholic beverages.
On the day of collection, have patient 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.
Keep the collected urine refrigerated.
Draw blood in the color-coded tube appropriate for the preservative or anticoagulant specified in the Specimen Requirements. Thoroughly mix the blood with the additives by gently inverting the tube 5-8 times. Store and transport at the temperature recommended under specimen requirements.
Category I Collection from Sterile Site
To collect specimens from these sites requires a needle puncture or a surgical procedure, so to reduce the risk of contamination. The skin must be cleansed.
Decontamination of the skin
- Clean the puncture site with 70% alcohol.
- Clean area with antiseptic providone-iodine preparation. Do not touch area with your finger.
Collection of Specimen
- Blood Cultures
Use the special blood culture sets provided by the Laboratory. Use one set of bottles for each specimen collection. When collecting more than one specimen (different sites of different times) use a separate set for each specimen collection. For example, one set for a specimen from the left arm; one set for the specimen from the right arm. Each blood culture set consists of one bottle of Columbia broth and one bottle of Trypticase broth. Multiple bottles from a single venipuncture must be considered a single culture set. We recommend two sets of blood cultures for most cases whenever possible. When infective endocarditic is suspected, three sets should be taken. If all three are negative after 24 hours, two or three more sets of blood cultures should be obtained. When multiple sets are taken, each set must be labeled with name, time specimen taken, and I or site or numbered #1, #2, #3 etc.
- Other body fluids
Collection of specimens by aspiration should be done following standard procedures. The specimen should be submitted in both anaerobic containers.
Category II Collection from a Non Sterile Site
The category is for those specimens collected through normally contaminated pathways such as urine and sputum.
Stool, throat, nasopharyngeal, and urogenital are the most common specimens in this category. Since these specimens have normal flora, it is very important that the emphasis be placed on the isolation of specific pathogens.
To insure the integrity of specimens during transport, the correct medium or preservatives must be used. The following is a list of transport media and preservatives provided by the laboratory for submission of specimens. It is of outmost importance that the correct medium or preservative be used.
- Routine culturette with clear gel or Culturette EZ (dry system).
Used for the transport of routine aerobic bacterial cultures. Will also support yeast.
- Culturette with charcoal gel.
Used for the transport of specimens when some fastidious organisms are suspected. Should be used for cultures of the cervix, vagina, endocervix, penis, urethra and when Neisseria species is suspected.
- Viral culturette
Effective transport for most common viruses such as Herpes Simplex, CMV, parainfluenza, and many other viruses.
- Chlamydia transport kit
Used to culture Chlamydia species.
- Sterile plastic containers ( 4oz I 118ml)
Used for the transport of some liquid and semiliquid specimens. Some examples are urine stool, semen and sputum.
- Gen-probe kit (pink) (females)
The pink colored kit is used for collection of cervical specimens for DNA probe test to detect Chlamydia trachomatis and I or Neisseria gonorrhea.
- Gen-probe kit (blue) (males)
The blue colored kits are used for conjuntival specimens and urethral specimens for DNA probe testing for Chlamydia trachomatis and Neisseria gonorrhea.
- Chlamydia trachomatis pathfinder kit
Used to collect and transport specimens for identification for Chlamydia trachomatis in direct urogenital and rectal areas from adults and ocular and nasopharyngel areas from pediatric patients.
- Herpes Simplex type 1 and 2 pathfinder kit
Used for collection and transport for identification of Herpes Simplex Virus in direct clinical specimens.
- Para-pack stool system
Used for transport of stool specimens for ova parasite testing.