The accuracy of the biochemistry tests and their interpretation is primarily dependent upon the quality of the submitted sample. Keep the following important factors in mind when submitting samples.
Fasting your patient before blood work is always desirable for all and essential for some blood tests. Please refer to the Available Tests for test specifications.
Sampling prior to therapy is vital to the reliability of most types of samples.
- Submit a complete clinical history including physical examination findings, current medication and time and date of obtaining the sample from the patient.
Selection of the proper volumes, type of samples and appropriate containers or vacutainer tubes (refer to Available Tests)
- Submission of volumes in excess of the requirement is ideal as it enables further investigation without resampling.
Turn Around Time
Routine Chemistry, Endocrinology, Hematology, Urinalysis and Serology will be reported by noon for samples arriving before 10:30 am and 5:00pm for samples arriving before 3:30 pm. Samples that arrive after 3:30 pm may be processed on the same day if the clinician deems the case to be urgent, otherwise testing will not be completed until the following day.
Emergency or “STAT” Requests
All requests for “STAT” service should be addressed to the laboratory. Consideration should be given to which individual tests are required “STAT” and which tests can be done at the standard work schedule. The Diagnostic Laboratory is always receptive to requests from submitters to send reports as soon as they are completed on critical cases.
Multiple Sample Submission
Diagnostic Cases – Requests involving more than 20 samples per case or per farm require 24 hours notice.
Herd Profiles – The laboratory will be able to do profiles on herds. In view of the expense involved it is important to carefully select the profiles and the specific tests required.
Research Projects – Projects involving many repeated samples or large batches or samples should be discussed with the laboratory prior to sampling.
The most frequent causes of inaccurate biochemical tests are:
- Aged sample
- Hemolysis, icterus and/or lipemia
- Insufficient sample quantity
- Drug interference from post therapy sampling or contamination
Test requirements for routine chemistry panels are specified on the submission form.
Test requirements for special chemistry are briefly outlined on the submission form and additional details are listed in the Fee Schedule. The following points apply to general specimen handling for clinical chemistry:
- THE SUBMISSION OF A WHOLE CLOTTED UNSEPARATED SAMPLE IS GENERALLY UNSATISFACTORY FOR MOST BIOCHEMICAL TESTS. Following clot retraction of the whole blood (allow 20-30 minutes at room temperature), rim the tube with a wooden applicator stick, centrifuge, aspirate the serum by pipette or syringe and place into a second red-stoppered tube or plastic screw capped shipping vial. Ensure that all red blood cells are removed to prevent hemolysis during shipping. Usually about 0.3 ml of serum can be obtained from each l ml of clotted blood. Additional centrifugation of the clot could yield additional serum if required. Label the separated sample as serum and submit fresh if delivery within 48 hours is possible or frozen if longer transit time is likely. Serum can ALWAYS be frozen and stored before shipment.
- When plasma samples are submitted they must be collected in proper vacutainers, such as heparin or sodium fluoride. Plasma is immediately separated by centrifugation, pipetted off and submitted in a red-stoppered tube or a plastic screw cap shipping vial. IT IS IMPORTANT WHEN SEPARATING SERUM OR PLASMA TO LABEL THE SAMPLE ACCORDINGLY. STATE THE TYPE OF ANTICOAGULANT USED.
- Any test requiring fresh frozen serum or plasma must be marked frozen on outside of the container and arrive in a frozen state.