2) Leave sample at 4°C overnight to allow the clot to contract.

3) Using a glass pasteur carefully loosen the clot from the sides of the tube. It is important not to lyse the red cells as they can not then be separated from the serum.

4) Centrifuge the serum at 4000 rpm for 20 minutes @ 4°C.

5) Remove the serum from the clot by gently pipetting off into a clean tube using a glass pasteur.

6) Label with the animal number, antigen, total bleed and date.

7) Store at -20°C.