Sample Submission

General Procedures

Investigators planning to submit samples for analysis must schedule the submission with the laboratory (626-7661) at least 2 days in advance for hematology submissions, at least 1 week in advance for serum chemistry submissions (due to the need to order reagents), and preferably as soon as the submission date for the samples is known. Unscheduled samples are strongly discouraged and will be processed only after scheduled submissions have been processed.

Before testing is performed, a Pathology Services Submission Form must be completed and submitted with the properly labeled sample(s). Forms may be filled out online or obtained at either CAF or the UAHS Business Office.

We utilize a courier system for pick-up and delivery of UAHS samples.  The drop off location is the UAC Business Office, room 1126. Here you will find submission forms, test information, a small refrigerator/freezer and Ziploc bags. You may also drop samples off at the front desk of CAF, where submission forms are also available. Samples must be dropped off at either location by 2:00 p.m. Monday-Thursday and noon on Friday. These deadlines allow us to perform the analysis in a timely manner.

Test results are distributed by e-mail whenever possible though campus mail is also utilized. Reports that include histology, microbiology, and reference lab testing may take several days to weeks to be finalized and distributed.

Please note that diagnostic testing of non-research related sick or injured animals may only be ordered by a UAC veterinarian or veterinary technician.

Please review the UAC Pathology Services Specimen Collection Guidelines for information on appropriate containers, protocols and storage.

Hematology and Blood Chemistry Sample Collection Instructions for Rodents

Ante-mortem procedure (serial blood collection): The submandibular vein, saphenous vein, tail vein, external jugular vein, and retro-orbital venous plexus can all be used for ante-mortem serial blood collections. We recommend the submandibular vein approach to minimize blood clot formation, which would render the sample unacceptable for hematologic analysis. Please see the following website for instructions on blood collection from the submandibular vein: Click Here. Information and training on this and other blood collection methods can be obtained through UAC Pathology Services at (520) 626-7661.

Terminal procedure (endpoint collection): Cardiocentesis is the preferred method of blood collection from rodents for endpoint hematologic and blood chemistry analyses. Blood collection is performed immediately after euthanasia (with carbon dioxide or other approved euthanasia method) or while animals are anesthetized with an appropriate general anesthetic (e.g. barbiturate, ketamine combination, inhalant anesthetic) prior to euthanasia. Cardiocentesis should not be performed in an unanesthetized rodent.

Supplies needed:

  • 1cc syringe, single use
  • 23 or 22 g x 1 inch needle, single use
  • For CBC: EDTA Microtainer® (VWR catalog #VT365973) or Microvette 100 (Sardstedt # 20.1278.100)
  • For Serum Chemistry: Heparinized Microtainer® (VWR #VT365958 or VT365971)

Procedure (for mice but will work well for other rodent species)


Label an EDTA and/or a heparinized tube for each animal from which blood will be collected and organized these as appropriate in a tube rack. Remove lids and keep within reach. Note: If samples for both hematologic and blood chemistry analyses are needed from one animal, EDTA samples (for CBC) should always be obtained first followed by heparinized samples (for serum chemistry). An assistant is beneficial for ensuring quick transfer and adequate mixing of blood for EDTA samples to prevent blood clot formation.

CBC submissions

Using the syringe and needle, withdraw ~100uL blood (or more if no serum is needed for blood chemistry analysis) from the heart of the animal. Enter percutaneously at the notch between the caudal rib and sternal xiphoid process and aim for the center of the thoracic cavity. The bevel of the needle should be up and the syringe plunger should be retracted and then returned to its original position prior to needle insertion to prevent the cardiac ventricular wall from occluding the needle orifice by too much initial suction. Gently retract the syringe plunger to provide steady blood flow into the syringe and collect the desired volume (80 microliter minimum; 250 microliter maximum for the EDTA tubes specified above). Remove the needle from the animal, immediately and carefully remove the needle from the syringe, and gently (to prevent hemolysis) but quickly (to prevent clotting) dispense the blood into the EDTA tube. Immediately replace the lid on the EDTA tube, gently invert the tube several times to ensure adequate mixing with the anticoagulant, and then place the tube on a mechanical rocker if available. It is critical to minimize the time between blood collection and placement into the EDTA tube as a delay of more than 5 seconds may cause blood clots within the sample, which will render the sample useless for hematologic analysis. Keep EDTA samples at room temp or cool in a refrigerator. They should not be centrifuged and should never be frozen or placed on ice.

Blood chemistry submissions

Use a new needle and syringe to collect more blood via cardiocentesis as described above (as much as possible up to 500 uL). Place the blood in the heparin tube, replace the lid, and mix briefly and gently (again to avoid hemolysis). Speed is not as critical as for the EDTA sample as chemistries can be performed on serum or plasma. Heparinized samples may be centrifuged, plasma placed into another tube, and refrigerated. See tabulated information on this website to determine if the serum or plasma may be frozen for the analyte(s) of interest.

CBC and blood chemistry submissions from same rodent

Alternatively, if the syringe is filling quickly and smoothly during the initial blood withdrawal, collect ~600uL of blood, and very quickly dispense 100uL of blood into the EDTA tube, replace lid and mix as above. The remaining blood can then be placed in the heparinized tube. This should only be attempted by individuals that have significant experience with cardiocentesis as minimizing the time between initiating blood collection and dispensing/mixing blood in an EDTA tube is critical for reasons stated previously.

Microtainer® is a registered trademark of Becton, Dickinson and Company