Prepare samples with iodine contrast agent
Applied iodine contrast agent to each leaf section by transferring the leaf sample to a Petri dish filled with 5 ml of 2% iodine, 4% potassium iodide (w/v) dissolved in water. Covered samples and incubated them at room temperature for 2 d before blotting them dry and pressing them flat in envelopes.
Quantities: 5 ml of 2% iodine, 4% potassium iodide (w/v) solution per sampleDuration: 2 days incubation at room temperatureConditions: Room temperature incubation
Equipment: Petri dish, envelopes
Micro-CT X-ray imaging with iodine contrast
Prepared leaves with iodine contrast agent by soaking each in a glass jar filled with 100 ml of 2% iodine, 4% potassium iodide (w/v) dissolved in water, covered samples and incubated them at room temperature for 2 d before blotting them dry and pressing them flat in envelopes. Immediately placed each leaf in the sample holder of an X-ray computed tomography system (FaCT; Moore, 2011). System generates polychromatic X-rays using a tungsten-anode, cone-beam-emission X-ray source operated at a voltage range of 20–155 kVp for currents up to 0.5 mA.
Quantities: 100 ml of 2% iodine, 4% potassium iodide solution, 20–155 kVp voltage range, up to 0.5 mA current, L + d fixed at 270 mm, magnification factor between 25 and 245 mm, 2048 × 1024 pixel silicon CMOS detector, 0.15 mA current, 6.7 s exposure timeDuration: 2 days incubation, 6.7 s exposure timeConditions: Room temperature incubation, University of Arizona's Radiology Research department
Equipment: glass jar, FaCT X-ray computed tomography system, tungsten-anode cone-beam-emission X-ray source, gadolinium oxide scintillator crystal, 2048 × 1024 pixel silicon CMOS detector