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

STAINING OF PRECIPITATION BANDS

• After optimal development of precipitation patterns, the plates can be stained for considerable improvement in sensitivity.
• The plates are submerged in normal saline and change saline in hourly intervals several times to remove non-precipitated proteins.
• Cracking of gel because of air bubbles can be avoided by filing the wells with a drop of agarose solution; Salt is removed by keeping the plates in distilled water for one hour.
• Gels are finally dried at 37 ⁰ C overnight by keeping a wet filter paper over them. After drying, filter paper may be removed by slight wetting.
• The gels are then stained for 15-30 minutes by using the Coomassie brilliant blue stain followed by destaining.

Limitation of Test

• The test antigen used in counter immunoelectrophoresis should have net negative charge at pH 8.6.