- Immediately place the sample in a sealed plastic bag (e.g. Zip-Loc). Label bag (tree, row, grower, GPS etc.).
- Do not add additional moisture in the bag.
- Do not allow the bag to sit in the sun (the samples heat very quickly).
- Keep the samples cool and shaded.
- If you use ice packs, do not place the bags with leaf samples directly against the ice pack. This will freeze the tissue and the lab will not be able to test the sample reliably. Use several layers of paper or bubble wrap to insulate the leaves.
NOTE: The virus distribution in plants is uneven, particularly with recent infections, and the virus concentration changes from season to season. The type of tissue and season are the critical factors influencing reliable results. Dormant bud sticks are often one of the best tissues for virus detection. Generally the virus concentration is reduced in the hot summer season (with exceptions). Suggestions for collecting different sample tissues are provided below for testing major stone and pome fruit viruses/diseases.