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

PROCEDURE

• The tube agglutination tests are more accurate than the plate test, but require relatively long incubation time.
• Set up six agglutination tubes in a row and add 0.8 ml of saline to tube No. 1 and 0.5 ml to the other five tubes.
• Add 0.2 ml of test serum to tube No.1. Mix well and then transfer 0.5 ml to tube No.2 Repeat two fold dilutions up to tube No.6 and then discard 0.5 ml (dilution 1:5, 1:10 and so on in each tube).
• Add 0.5 ml of plain antigen to each tube and mix well (final dilution of serum resulted will be 1:10, 1:20 and so on).
• Control tubes are also set in the test.
• Positive control with 0.5 ml of known positive serum and 0.5 ml plain antigen.
• Negative control with 0.5 ml saline and 0.5ml plain antigen.
• Tubes 6,7,8,9, and 10 serve as antigen control as well as 0,25,50 and 100 % agglutination standard respectively. (Opacity of the suspension to be compared with the opacity of the suspension in tubes 1 to 5).
• Because of the special significance of the 50% end point, control tube should be set up with 0.75 ml saline and 0.25 ml plain antigen.
• All tubes are then incubated at 37 ⁰ C for 18-20 hour before the results are read.

Courtesy: http://blog.labplanet.com/wp-content/uploads/2011/03/tube-agglutination-test.bmp