Specimen Collection and Preparation.fm - Mayo Clinic



Specimen Collection and PreparationAccuracy of laboratory testing depends on the quality of the specimen submitted. Proper specimen collection, identification, and transport determine the accuracy and utility of the test results. Please consult the alphabetical test listings for information about collection and handling of specimens. If there are any questions, please call IU Health Bloomington Laboratory at 812-353-9897 or 812-353-9435 to clarify the specimen requirements. For a limited number of tests, handling requirements dictate collection of the specimen only at the hospital or only during limited hours.Blood CollectionPlasma and Whole Blood: Draw a sufficient amount of whole blood into a tube containing the proper anticoagulant. Immediately invert the tube gently several times to mix. Unless whole blood is required, separate the plasma from the cells by centrifugation within 30 minutes. Examples of anticoagulant collection tubes include the following: green-top (lithium or sodium heparin), lavender-top (EDTA), light blue-top (sodium citrate), and lavender-top (K2 EDTA).Note: If test requires whole blood, do not use a plasma geltube. Some drug levels performed on plasma cannot be performed on plasma from a plasma gel tube. Instructions for platelet poor plasma:Some tests require double spinning of the blue top tube to obtain platelet poor plasma. Centrifuge for 6-10 minutes at 3500 rpm. Transfer plasma, leaving a thin layer of plasma (about 1/8 inch) in the primary tube, into a plastic aliquot tube. Centrifuge aliquot tube for 6-10 minutes at 3500 rpm. Transfer plasma into a new aliquot tube again leaving a thin layer of plasma. Freeze plasma ASAP. Serum: Draw a sufficient amount of whole blood into a plain, red-top tube or a gold-top (serum gel) tube. If using a gold-top (serum gel) tube, gently invert the tube several times to activate clotting. Allow blood to clot at ambient temperature for 20 to 30 minutes. Centrifuge for 6-10 minutes to separate serum from clot, depending on the type of centrifuge used. If using a plain, red-top tube, after centrifugation transfer the serum to a screw- capped, plastic vial within 1 hour of drawing the specimen if required. If a specimen is to be centrifuged, do not stop the centrifuge once started; interrupting the process may degrade specimen integrity.Note: There are some tests requiring serum for which gold-top (serum gel) tubes should not be used. These are identified in the individual test listings. If you are not sure if a gold-top (serum gel) tube is acceptable, a plain, red-top tube is always acceptable.Blood Specimen Collection TubesThe following is a list of tubes referred in our specimen requirements:? Light Blue-Top (Buffered Sodium Citrate) Tube: This tube contains 3.2% buffered sodium citrate as an anticoagulant and is used for coagulation studies.Note: It is imperative that the tube be completely filled.The ratio of blood to anticoagulant is critical for valid results. Immediately after draw, invert tube8 to 10 times to prevent clotting.? Red-Top (Plastic) Tube: This tube contains no anticoagulants and is used for selected chemistry tests requiring serum and for selected immunohematology tests requiring clotted blood.? Gold-Top (Serum Gel [Gel and Clot Activator]) Tube: This tube contains a clot activator with a gel barrier and is used for various tests.Note: After tube has been filled with blood, invert 8 to10 times to activate clotting; let stand for 20 to 30 minutes. Centrifuge for 6-10 minutes, depending on the type of centrifuge used. If frozen serum is required, pour off serum into plastic vial and freeze. Do not freeze gold tubes.? Light Green-Top (4.5 mL Lithium Heparin, Plasma Gel) Tube: This tube contains lithium heparin as an anticoagulant with a gel barrier for separation and isused for the collection of heparinized plasma.Note: After tube has been filled with blood, immediately invert tube 8 to 10 times to prevent clotting. Centifuge for 6-10 minutes, depending on the type of centrifuge used.? Green-Top (4 mL Lithium Heparin) Tube: This tube contains lithium heparin as an anticoagulant with no gel barrier. Plasma from these tubes should be tested or removed from tube within 4 hours of draw, depending on the analyte.? Lavender-Top (EDTA) Tube: This tube contains EDTA as an anticoagulant and is used for most hematological tests.Note: After tube has been filled with blood, immediately invert tube 8 to 10 times to prevent clotting.? Lavender-Top (K2 EDTA) Tube: This tube contains K2EDTA as an anticoagulant and is used for most blood bank tests.Note: After tube has been filled with blood, immediately invert tube 8 to 10 times to prevent clotting.? Grey-Top (Potassium Oxalate/Sodium Fluoride) Tube: This tube contains potassium oxalate as an anticoagulant and sodium fluoride as a preservative. It is used to preserve glucose in whole blood and for some special chemistry tests.Note: After tube has been filled with blood, immediately invert tube 8 to 10 times to prevent clotting.? Large Green-Top (10 mL Sodium Heparin) Tube: This tube contains sodium heparin as an anticoagulant and is used for the collection of heparinized plasma or whole blood for special tests. Note: After tube has been filled with blood, immediately Invert tube 8 to 10 times to prevent clotting. ? Royal Blue-Top (K2 EDTA [Lavender Label]) Tube: This tube contains EDTA anticoagulant and is used for trace metals analysis.Note: After tube has been filled with blood, immediately invert tube 8 to 10 times to prevent clotting.? Royal Blue-Top (Red Label) Tube: This tube contains no anticoagulant and is used for trace metals analysis.Note: Refer to the individual metals tests in the alphabetic test listing to determine the tube type necessary.? Yellow-Top (ACD) Tube: There are 2 types of ACD tubes, ACD solution A (8.5 mL) and ACD solution B (6 mL). These tubes contain acid citrate dextrose (ACD) and are used for special tests.Note: After tube has been filled with blood, immediately invert tube 8 to 10 times to prevent clotting.? Special Collection Tubes: Some tests require specific tubes for proper analysis. Please call IU Health Bloomington Laboratory Sendouts Department at 812-353-5698 prior to venipuncture to obtain the correct tubes for metals analysis or other tests as identified in the alphabetic test listings.Prevention of Backflow During Blood DrawSince some blood collection tubes contain chemical additives which could cause adverse patient reactions, it is important to avoid possible back flow from the tube. To guard against backflow, observe the following precautions:? Place patient’s arm in a downward position.? Hold tube with the stopper uppermost.? Release tourniquet as soon as blood starts to flow into tube.? Make sure tube additives do not touch stopper or end ofthe needle during venipuncture.Recommended Order of Blood Draw? Tubes for sterile specimen (blood cultures).? Tubes for coagulation studies (light blue-top).? Red-top serum tube.? Serum tube with or with out additive (gold-top [serum gel] or trace metal, no additive tube).? Green-top (lithium or sodium heparin) or plasma gel tube.? Lavender-top (EDTA) tube.? Grey-top (potassium oxalate/sodium fluoride) tube.Gold-top (serum gel) tubes and VACUTAINER? PLUS serum tubes contain particulate clot activators and are considered additive tubes. Therefore, VACUTAINER? PLUS serum tubes are not to be used as discard tubes before drawing blue-top citrate tubes for coagulation studies.Specimen CentrifugationCentrifuge carriers and inserts should be of the size specific to the tubes used. Use of carriers too large or too small for the tube may result in breakage. Ensure that tubes are properly seated in the centrifuge carrier. Incomplete seating could result in separation of the Becton Dickinson (BD) Hemogard? Closure from the tube or extension of the tube above the carrier. Tubes extending above the carrier could catch on centrifuge head, resulting in breakage. Balance tubes to minimize the chance of breakage. Match tubes to tubes of the same fill level, glass tubes to glass tubes, plastic tubes to plastic tubes, tubes with BD Hemogard? Closure to others with Hemogard? Closure, gel tubes to gel tubes, BD VACUTAINER? PLUS tubes with PLUS tubes, and tube size to tube size.If the tube requires centrifugation, spin for 6-10 minutes depending on the type of centrifuge used, at 3,500 rpm unless otherwise instructed. If a specimen is to be centrifuged, do not stop the centrifuge once started; interrupting the process may degrade specimen integrity. Always allow centrifuge to come to a complete stop before attempting to remove tubes. When centrifuge head has stopped, open the lid and examine for possible broken tubes. If broken, use mechanical device such as forceps or hemostat to remove tubes. Note: Do not remove broken tubes by hand. See centrifugeinstruction manual for disinfection instructions.Histology SpecimensRoutine Specimens Submitted to Histology for Tissue Processing:? Specimen container and requisition must include:— Patient name--- Date of birth— Type of tissue— Physician name, first and last name— Body site— Collection date? The requisition must also include the physician’s signature. If a duplicate report is required, please include the first and last name of the physician who is to receive the copy.? Specimens received for routine histological examination must be submitted in 10% neutral buffered formalin.Pre-filled containers labeled “10% Formalin” are provided to all doctors’ offices and nursing units. Specimens from Surgery are also sent in pre-filled, labeled formalin containers.? Transport specimens at ambient temperature.? Please call the Histology Department at 812-353-5588 with any questions regarding collection procedures.Renal Stones Submitted to Histology for Tissue ProcessingLEEP Cervical Cone Specimens Submitted To Histology for Tissue Processing:? Specimens collected off site should be opened and placed in a tissue cassette and submitted in formalin.? Send stones to histology with no fixation (do not submit in formalin).? Specimen container and requisition must include:—Patient name---Date of birth— Type of tissue— Body site— Collection date— Physician name, first and last name? The requisition must also include the physician’s signature. If a duplicate report is required, please include the first and last name of the physician who is to receive the copy.Immunofluorescence Specimens (ie, skin biopsies for vesiculo bullous disease) Submitted to Histology Requiring Special Fixatives:? Please call the Histology Department at 812-353-5588 prior to specimen collection for supplies and further instructions.Lymph Nodes Submitted to Histology for Tissue Processing, or any Specimen Requiring Lymphoma Work-up:? Send fresh specimen on saline-moistened gauze to theHistology Department as soon as possible.? Notify the department immediately.Cold Knife Cervical Conization Specimens Submitted to Histology for Tissue Processing:? Specimens collected onsite and off site may be submitted fresh (no formalin) to the Histology Department as soon as possible.? Cold knife cervical conization specimens may also be opened by the surgeon, pinned to a paraffin block, and submitted in formalin. ................
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