Transfer each subsample of seeds into a radiation sterile
Stomacher bag (e.g. 105 9 50 mm) and add 3 mL sterile
PBS-T per g seed (Appendix 2). Soak and refrigerate seeds
overnight (minimum 14 h) under refrigeration. Crush the
seeds for 3 min in a Stomacher and allow the sediment to
settle for 30 min at room temperature.
Filter the resulting homogenate through sterile gauze and
centrifuge the filtrate at 10 000–12 000 g for 20 min at
10°C. Remove the supernatant and resuspend the pellet in
1.0–1.5 mL sterile water to obtain the final concentrate.
Prepare 10-fold dilutions for direct isolation.
Aliquots of each seed extract can be frozen as a reference
and used for any further testing.