Procedure

PROCEDURE

  • Add 25 μl of normal saline in all the wells.
  • Add 25 μl of the virus containing allantoic fluid in the first well and make serial two-fold dilution. Discard 25μl of the suspension from the eleventh well.
  • Add 25 μl of normal saline in all the wells
  • Add 25 μl of 1% chicken RBCs in all the 12 wells. The last well is considered as RBC control.
  • Shake the plate and leave it for 40 minutes at room temperature.
  • Look for lattice formation ie. Haemagglutination. The end point is the reciprocal of the highest dilution showing 100% haemagglutination. The control well should show button formation
  • Calculation of 4HA
      • 4 HA = HA titre / 4
      • Example: When HA titre = 128, 4 HA = 128 /4 = 32
  • 1 ml of the virus containing allantoic fluid + 31 ml of the sterile normal saline will give a suspension that has 4 HA in every 25 μl. This will be used to conduct HI test.

Haemagglutination test

In this figure HA titre = 1024 (210)

HA follwed by HI with known specific antiserum can be used for diagnostic purpose (e.g. Newcastle disease)
Last modified: Tuesday, 17 April 2012, 10:41 AM