# Council Directive 98/57/EC of 20 July 1998 on the control of Ralstonia solanacearum (Smith) Yabuuchi et al., Division: Principle

Extent: E+W+S+N.I.

When the FISH test is used as the first screening test and found to be positive, Isolation or the IF test must be performed as a second compulsory screening test. When the FISH test is used as the second screening test and found to be positive, further testing according to the flow scheme is required to complete the diagnosis.
The following procedure should preferably be performed on freshly prepared sample extract but can also be successfully performed on sample extract that has been stored under glycerol at -16 to -24 or -68 to -86 °C.
As negative controls, use aliquots of sample extract that previously tested negative for R. solanacearum .
As positive controls prepare suspensions containing 10 5 to 10 6 cells per ml of R. solanacearum biovar 2 (e.g. strain NCPPB 4156 = PD 2762 = CFBP 3857, see Appendix 3) in 0,01M phosphate buffer (PB) from a 3 to 5 day culture). Prepare separate positive control slides of the homologous strain or any other reference strain of R. solanacearum , suspended in potato extract, as specified in Appendix 3 B.
The use of the FITC-labelled eubacterial oligo-probe offers a control for the hybridisation process, since it will stain all eubacteria that are present in the sample.
Standardized positive and negative control material available for use with this test are listed in Appendix 3A).
Test control material in an identical manner as the sample(s).

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Source: https://www.legislation.gov.uk/eudr/1998/57/annex/II/section/VI/division/A/division/7/division/1 (the official version)
Page: https://openlegislation.uk/eu-directive-1998-57/annex-II/section-VI/division-A/division-7/division-1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.