specialists in coagulation testing









Introduction

Specimen processing is one of the most important aspects in the generation of accurate and reliable lab results. Many variables, such as, anticoagulant ratio, storage time and temperature, and surface of containers and drawing components can effect test results.

Machaon Diagnostics follows and recommends the use of the third edition of the National Committee for Clinical Laboratory Standards (NCCLS) guideline H21-A3: Collection, Transport, and Processing of Blood Specimens for Coagulation Testing and General Performance of Coagulation Assays.

PLEASE CALL THE LAB WITH ANY PROCESSING QUESTIONS
1-800-56-MD-Inc (6-3462)


Specimen Collection

Frozen Citrated Plasma
Frozen citrated plasma is the specimen of choice for clotting assays and some ELISA testing. The anticoagulant used for these assays is 105 - 109 mmol/L, 3.13% - 3.2% of the dihydrate form of trisodium citrate (Na3C6H5O7 2H2O), buffered or nonbuffered.

Patients with hematocrit values above 55% should have their final citrate concentration corrected using the following equation:

X = (100 - PCV) / (595 - PCV) WB Volume

Where X is citrate volume required to prepare a whole blood volume (WB Volume) from a patient with a certain percent packed cell volume (PCV).

Please follow the listed suggestions for collection of citrated plasma samples.

  • A 1:9 ratio of anticoagulant to whole blood is imperative
  • Blood should be drawn directly into anticoagulant if possible
  • Syringe draws should be added to anticoagulant within 1 minute
  • Syringe draws should use no more that a 20mL volume syringe
  • A two-syringe technique is preferred for syringe draws
  • Coagulation draws should be the 2nd or 3rd tube drawn
  • Catheter draws should be avoided or under the advise of the attending physician
  • All tubes should be inverted at least 4 times to ensure adequate mixing
  • Suitable needle gauges range from 19 - 22 for coagulation and platelet testing
  • Cell-free plasma must contain less than 10,000 platelets/µL
  • Centrifugation should be performed at 1,500 × g for 15 or more minutes
  • Aliquots are frozen (<= -20ºC) promptly to minimize factor degradation
  • Specimens are shipped frozen on dry ice (-78.5ºC)

Frozen Serum
Frozen serum is the specimen of choice for most immunoglobulin detecting assays and many ELISA based tests. Whole blood is drawn into a glass or plastic tube possibly containing an activator. Please follow the tube manufacturer's guidelines for tube handling and processing.

Please follow the listed suggestions for collection of serum samples.

  • Plastic tubes containing an activator should be inverted at least 4 times
  • Glass tubes without activator should be clotted for 2 hours at room temperature
  • Suitable needle gauges range from 19 - 22 for the serum based tests
  • Centrifugation should be performed at 1,500 × g for 15 or more minutes
  • Aliquots are frozen (<= -20ºC) before shipping and shipped on dry ice (-78.5ºC

EDTA Whole Blood
EDTA anticoagulated whole blood is the specimen of choice for molecular genetic tests.

Please follow the listed suggestions for collection of genetic samples.

  • Blood should be drawn directly into anticoagulant if possible
  • This must be a closed system draw to prevent contamination
  • All tubes should be inverted at least 4 times to ensure adequate mixing
  • Suitable needle gauges range from 19 - 22 to prevent cell lysis
  • A minimum of 2mL of whole blood is needed for genetic assays
  • No processing is required for this sample type
  • Ship this type of specimen at room temperature

Aliquoting Specimens
Submitting multiple aliquots (plasma or serum) for testing is an important aspect of clot, chromogenic and ELISA based tests. Aliquots of 1mL are requested for most of our assays. These should be frozen prior to shipment in a <= -20 C freezer or colder. Tubes should be placed into a rack to ensure the samples are frozen properly in the base of the tube. Freezing should occur within 1 hour of the time of draw. Please refer to the preferred number of aliquots when submitting samples.

Shipping
Shipment is a crucial aspect of clinical testing. Please follow the below instructions for easy shipments to the lab.

Local Shippers
Machaon Diagnostics contracts with Medical Couriers, Inc. (MCI). who service the entire San Francisco Bay Area and surrounding areas. MCI has a fleet of specially trained drives that will visit your lab, clinic or office during specified times. Couriers carry dry ice, cold packs and room temperature containers for receipt of all specimen types.

Medical Couriers, Inc. can be phoned for individual pickup requests at the below number.

Medical Couriers, Inc.
(800)-652-1147

Place prepare samples and order form in a shipping bag with Machaon and specimen type written in a clear and visible location.

Out-of-area Shippers
Please collect the following items:

  1. Test Order Form
  2. Packing material or newspaper
  3. Styrofoam container, possibly with outer cardboard box
  4. Packaging tape
  5. Airbill for overnight shipments
  6. ORM-A label for dry ice shipments (UN1845)
  7. Dry ice (-78.5ºC) sufficient for transit time (5lb. per day)
  8. Specimens in biohazard specimen transport bag

Packaging
Place the biohazard bag containing samples and the test order form into a Styrofoam container followed by dry ice. Fill remaining container space with packaging material and seal with packaging tape. Adhere a completed airbill and dry ice labels to the exterior of container in a visible location. Telephone your preferred overnight courier to request a pickup or place container in designated pickup area.

PLEASE CALL THE LAB WITH ANY SHIPPING QUESTIONS
1-800-56-MD-Inc (6-3462)
 
© 2008 Machaon Diagnostics, Inc.