{
  "url": "https://openlegislation.uk/eu-directive-1998-57/annex-II/section-II/division-3",
  "json_url": "https://openlegislation.uk/eu-directive-1998-57/annex-II/section-II/division-3.json",
  "legislation": "eudr/1998/57",
  "legislation_title": "Council Directive 98/57/EC of 20 July 1998 on the control of Ralstonia solanacearum (Smith) Yabuuchi et al.",
  "legislation_url": "https://openlegislation.uk/eu-directive-1998-57",
  "path": "annex/II/section/II/division/3",
  "kind": "division",
  "number": "3",
  "heading": "Isolation procedure",
  "text": "(a) Remove ooze or sections of discoloured tissue from the vascular ring in the potato tuber or from the vascular strands in stems of potato, tomato or other wilting host plants. Suspend in a small volume of sterile distilled water or 50mM phosphate buffer (Appendix 4) and leave for 5 to 10 minutes.\n(b) Prepare a series of decimal dilutions of the suspension.\n(c) Transfer 50-100 µl of the suspension and dilutions to a general nutrient medium (NA, YPGA or SPA; see Appendix 2) and/or to Kelman’s tetrazolium medium (Appendix 2) and/or a validated selective medium (e.g. SMSA; see Appendix 2). Spread or streak with an appropriate dilution plating technique. If useful, prepare separate plates with a diluted cell suspension of R. solanacearum biovar 2 as a positive control.\n(d) Incubate the plates for two to six days at 28 °C.\nOn the general nutrient media, virulent isolates of R. solanacearum develop pearly cream-white, flat, irregular and fluidal colonies often with characteristic whorls in the centre. Avirulent forms of R. solanacearum form small round non-fluidal, butyrous colonies which are entirely cream-white.\nOn Kelman’s tetrazolium and SMSA media, the whorls are blood red in colour. Avirulent forms of Ralstonia solanacearum form small round non-fluidal, butyrous colonies which are entirely deep red.",
  "extent": "E+W+S+N.I.",
  "status": null,
  "version": "current",
  "annotations": [
    {
      "type": "F",
      "label": "F1",
      "text": "Substituted by Commission Directive 2006/63/CE of 14 July 2006 amending Annexes II to VII to Council Directive 98/57/EC on the control of Ralstonia solanacearum (Smith) Yabuuchi et al.."
    }
  ],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/eudr/1998/57/annex/II/section/II/division/3",
    "retrieved_at": "2026-11-01T15:23:06.931886+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}