VMC 221: Veterinary Immunology and Serology (1+1)

PROCEDURE

• In poultry, blood is usually collected from the wing vein. If more quantity is required, cardiac puncture method may be followed.
• 1-2 ml of blood is collected from wing vein into a vacutainer tube using a vacutainer needle fitted with its adapter or test tubes with wider surface area may be used instead of long and slim tubes.
• The area of the wing vein is wiped of with tincture iodine.
• The collected blood should be kept in a slanting position at 37 ⁰ C until the blood clots. The clot should be frequently disturbed by running the chromium wire around the edge of the clot.
• Collect the straw yellow colored fluid that settles at the bottom of the tube displacing the clot.
• Centrifuge it for 5 minutes at 2500 rpm. Serum will remain at the top and the RBCs will settle at the bottom.
• Care should be taken to avoid collecting free RBC with the serum.
• Blood clots better in glass when compared to plastic containers.
• Serum should be heat inactivated at 56 C for 30 minutes , before  frozen at –20 ⁰ C for long term storage, but repeated freezing and thawing should be avoided.
• Protein denaturation at room temperature is minimal if serum is sterilized by filter (0.22-0.45 micron). For filter sterilization the serum volume should be about 20ml.
• Storage at 4 ⁰ C is possible after the addition of merthiolate.
• Preservation of non-sterile serum for transport without refrigeration can be achieved by addition of 0.5% V/V chloroform.
• Serum may also be preserved in ice, by addition of 50% glycerol saline at the ratio of 1:1. The addition of glycerol saline does not interfere with any serological reaction.