The Serology section of the Animal Health Centre (AHC) offers serological testing for a wide range of avian and mammalian pathogens primarily utilizing ELISA (Enzyme Linked Immunosorbent Assay) methods.
In addition to routine diagnostic testing, the Serology section undergoes proficiency testing conducted by the Canadian Food Inspection Agency, National Centre for Foreign Animal Disease and the USDA's National Veterinary Services Lab.
The Serology section is accredited by the CFIA for Equine Infectious Anemia and Brucellosis (BPAT) testing. This lab is also an approved Johne's disease (M. avium subsp. paratuberculosis) testing lab, having successfully passed NVSL serology panels since 1999.
Serology Samples - Submission Requirements
Serological tests can be used to determine:
- if an animal has been infected by a particular pathogen
- if a specific pathogen is linked to a clinical disease
- if an animal has elicited an antibody response following vaccination
A single serum sample from an animal provides some indication of exposure to a pathogen at a point in time. However, paired serology on 5-10 age matched cohorts including clinically affected and apparently healthy animals is necessary to assess the potential disease dynamics within a group of animals. Acute and convalescent-phase sera collected from the same animal constitute paired sera. The acute-phase serum is taken as soon as the animal first develops clinical signs and the convalescent-phase samples usually at least 2 weeks later. Paired sera should be submitted together.
Enzyme linked immunosorbent assay (ELISA), Agar Gel Immunodiffusion (AGID), hemagglutination inhibition (HI) and virus neutralization (VN) are the major serological assays performed at the AHC. Additionally, AHC performs radial immunodiffusion (RID) assay for total antibody quantification in cattle and horses.
Guidelines for Serum Samples
Quality of serum samples submitted for serological assays can have a significant impact on final assay results. For example, hemolyzed or lipemic serum can lead to unreliable test results. Please use the following guidelines to submit serum samples to ensure timely service and accurate test results:
- Use serum tubes or serum separation tubes for collection
- DO NOT use EDTA (lavender-top), heparin (green-top) or citrate (blue-top) tubes
- After collection keep the blood samples at room temperature until serum has separated from the clot (30-60 minutes).
- Centrifuge at 1100-1300 rpm for 15 minutes
- Submit serum only. Even if serum separation tubes are used for collection, please pour/draw off serum into separate clean tubes. Ship samples to the laboratory with ice packs to keep sera cold while in transit
- If samples cannot immediately be transported to the laboratory, refrigerate the serum at 2–7°C for up to 3–5 days or freeze at 20°C for long term storage
Freeze and thaw cycles during shipping and/or storage can lead to hemolysis, if serum is not separated from the clot
- Submit a minimum of 2 ml serum for large animals. In the case of poultry 0.5ml serum must be submitted from each bird
- Outside of the tubes must be clean and dry to avoid contamination. Label the tubes with ID numbers using permanent marking pen on the side of the tube
- Place the tubes with serum in consecutive numerical order in Styrofoam or cardboard boxes designed to hold the tubes. Do not submit in bags
- When submitting more than 20 samples at a time, please send an MS Excel file with Animal IDs by e-mail to PAHB@gov.bc.ca. Enter animal IDs in a single column identified as “Animal ID” and the AHC report will contain IDs as entered in this column. Place samples in the same order in the rack/box as in the MS Excel file
DO NOT submit serum samples that are grossly hemolyzed (dark-red color) or lipemic (milky appearance).