Methods of internal standards’ preservation for genome size assessments: a comparative study

Assessing genome size in plant species using flow cytometry requires fresh plant material from both the target species and appropriate internal standards. The use of fresh material from the standards is sometimes difficult. For this reason, a research about three preservation methods and their results when using the plants in flow cytometry has been conducted. We have focused on four of the most used internal standards in flow cytometry to estimate the nuclear DNA amount. Our results pointed out that the best method of conservation was lyophilisation. The conservation method based on drying with silica gel is more advisable to establish the ploidy level than to provide an absolute value of nuclear DNA content. Finally, ultrafreezing is not an appropriate preservation method