Ascoli’s thermo precipitation test

ASCOLI'S THERMO PRECIPITATION TEST

  • This test is used for diagnosis of Anthrax. In advanced decomposition of carcass and when microscopical examination is almost impossible, the precipitation method of Ascoli is used for diagnosis of Anthrax. This method is a mixing of immunized rabbit serum with an extract of organs under examination for the production of a precipitate.

Procedure

  • Grind up the organs (e.g. muzzle) of suspected animals.
  • Suspend in saline.
  • Boil for five minutes
  • Filter through filter paper or muslin cloth and allow to cool
  • Carefully add 0.5 ml of this extract in a small test tube and 0.5 ml hyper immune serum is poured into gently through the wall of the test tube.
  • Allow to stand for 15 minutes at room temperature.
  • Definite ring like precipitate forms at junction of two fluids in positive cases.
  • Control tests should be run with known anthrax positive extract and with normal saline (negative control).
Last modified: Saturday, 24 September 2011, 4:44 AM