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

PREPARATION OF EMULSION

Syringe with locking hubs (Luer – Lock needle)

• Three way locking hubs can be used for preparation of emulsion. The outlet way is closed using the locking system and one syringe containing the required antigen is fitted to one side of the hub, to the other side, another syringe containing the adjuvant is fitted.
• Mix both the contents gently until a through emulsion is obtained. The emulsion turns milky white on through emulsification.

Double hubbed needle method

• In this method, two needles of 18 G size are welded together at their pointed end. Any obstruction or leakage should be checked. Both the hubs are connected with syringes.
• One of the syringes is filled with FIA or FCA half the volume and another with a equal volume of antigen solution. Air space is avoided. Then the antigen solution is passed into the oil and the mixture is passed backward.
• Likewise the mixture is pushed backward and forward until the emulsion is obtained.

Vortexing

• Nowadays, many laboratories mix the two with antigen in aqueous solution being added in small (10 ml) aliquot to FIA with repeated vortexing.
• The final emulsion should be white thick and creamy and should not separate after standing for some hours. The emulsion can be checked by placing a drop of the prepared emulsion in a beaker containing water to see that the emulsion drop does not dissociate.