Animal Health Diagnostic Center

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Comparative Coagulation


Sampling for all coagulation and vWF assays

The accuracy and validity of hemostasis testing depends on sample quality!

Technique for collection of whole blood in citrate anticoagulant:

DOGS, CATS, PRIMATES, RABBITS

  • Syringe Method

Draw citrate anticoagulant (3.8% Na citrate) into a plastic syringe and then perform venipuncture using a ratio of 1 part citrate: 9 parts blood as follows:
0.3 mL citrate plus 2.7 mL blood = 3.0 mL total sample
0.4 mL citrate plus 3.6 mL blood = 4.0 mL total sample
0.5 mL citrate plus 4.5 mL blood = 5.0 mL total sample
(CITRATE TO WHOLE BLOOD RATIO IS CRITICAL)

  • Vacutainer Method:

Use a vacutainer needle or vacutainer butterfly set to draw blood directly into a 3 or 5 ml sodium citrate vacutainer tube. A COMPLETE DRAW MUST BE OBTAINED.

LARGE ANIMALS (COW, HORSE, SHEEP, GOAT)

Use a vacutainer needle and draw blood directly into a 5 - 10 mL blue top (3.8% Na citrate) vacutainer tube. A COMPLETE DRAW MUST BE OBTAINED.

LABORATORY ANIMALS (RODENTS, SMALL MAMMALS):

  • (Do not use the eye orbital vein or tail vein collection technique)
  • Anesthesia (deep surgical plane) is necessary for blood collection. Suitable anesthetic agents include pentobarbital or ketamine/xylazine.
  • Incise the body wall and peritoneum on the ventral midline in order to expose the abdominal aorta for needle puncture.
  • Place citrate anticoagulant (3.8% Na citrate) into a plastic syringe and then draw blood using a 22 or 23 gauge needle. The ratio of citrate to blood must be exactly 1: 9 as in the following examples:

0.1 mL citrate plus 0.9 mL blood = 1.0 mL total sample
0.2 mL citrate plus 1.8 mL blood = 2.0 mL total sample
0.3 mL citrate plus 2.7 mL blood = 3.0 mL total sample
(CITRATE TO WHOLE BLOOD RATIO IS CRITICAL)

Plasma separation and storage:

  • Centrifuge whole blood in a plastic or siliconized glass tube for 1 min. in a microfuge or for 10 min. in a tabletop centrifuge.
  • Transfer PLASMA ONLY into a plastic tube using a plastic pipet
  • Store samples frozen (-70oC to -20oC) until shipment

Shipping requirements:

Shipping address:

Comparative Coagulation Section-Animal Health Diagnostic Center
College of Veterinary Medicine, Cornell University

(Address for US Postal Services)
P.O. Box 5786
Ithaca, NY 14852-5786

(Address for FedEx/UPS and other Courier Services)
240 Farrier Rd.
Ithaca, NY 14853

Cornell CVM or on-campus submissions:

Citrate whole blood samples can be dropped off at the Diagnostic Center receiving window for processing from 8:00 AM to 5:00 PM

After hours

Store separated citrate plasma in the refrigerator (no longer than overnight - 18 hours). Transport to the Diagnostic Center first thing in the morning.

Note - Platelet function testing requires 24 hours notice and specific arrangement with the Coagulation Section (call 253-3648). Samples must remain at room temperature until transport to the Coagulation Section.

Video of Sampling Techniques