Division 1.7.3 Cultivation

To reduce the frequency of culture maintenance (e.g. when no Lemna tests are planned for a period), cultures can be held under reduced illumination and temperature (4-10 °C). Details of culturing are given in Appendix 2. Obvious signs of contamination by algae or other organisms will require surface sterilisation of a sub-sample of Lemna fronds, followed by transfer to fresh medium (see Appendix 2). In this eventuality, the remaining contaminated culture should be discarded.

At least seven days before testing, sufficient colonies are transferred aseptically into fresh sterile medium and cultured for 7-10 days under the conditions of the test.