Division 3 Serological agglutination testsF1

Agglutination of R. solanacearum cells in bacterial ooze or symptomatic tissue extracts is best observed using validated antibodies (see Appendix 3) labelled with appropriate coloured markers such as red Staphylococcus aureus cells or coloured latex particles. If using a commercially available kit (see Appendix 3), follow the manufacturers instructions. Otherwise perform the following procedure:

1. (a)

   Mix drops of a suspension of labelled antibody and bacterial ooze (approximately 5 µl each) on windows of multiwell test slides.

2. (b)

   Prepare positive and negative controls using suspensions of R. solanacearum biovar 2 and a heterologous strain.

3. (c)

   Observe for agglutination in positive samples after gentle mixing for 15 seconds.