Contrast-enhanced 3D micro-CT of plant tissues using different impregnation techniques

Table 1 Summary of experimental protocols used for contrast delivery

Samples	Incubation timeframe		Quick summary
Samples	Duration	Successful?^a	Remarks	Active delivery necessary?
Passive delivery
Apple hypanthium	30, 60, 90 min	–	Inconsistent and incomplete contrast penetration to center of sample, some edges detectable but fragmented	+
Pear hypanthium	30, 60, 90 min	+	Consistent and sufficient contrast throughout sample, with detectable intercellular boundaries	−
Tomato mesocarp	30, 60 min	–	Sample damage and destruction notable, incubation time/interval too long	−
Tomato mesocarp	5, 10, 15 min	+	Consistent and sufficient contrast throughout sample, detectable intercellular boundaries. Sample damage starts to be observable at 15 min	−
Tomato petiolule	30, 60, 90 min	+	Consistent and sufficient contrast throughout sample, detectable cell edges in parenchyma and collenchyma	−
Tomato leaflet	1, 2, 3, 4, 5 h	–	No detectable separation between mesophyll cells	+
Tomato leaflet	10 h	–	Sample oversaturated with contrast solution	+

Samples	Vacuum profile		Results
Samples	Duration + pressure	Successful?	Remarks
Active delivery
Apple hypanthium	[3 min @ 20 kPa, 10 min @ ambient] X2	−	Incomplete penetration to center of samples, edges detection inconsistent in cell clusters
Apple hypanthium	[5 min @ 20 kPa, 15 min @ ambient] X3	+	Consistent contrast movement through sample with easily detectable edges
Leaflet	[3 min @ 20 kPa, 10 min @ ambient] X2	−	Sample destabilized, movement artifacts frequent and severe. Large sections of leaflet flooded with contrast with no detectable intercellular boundaries

^aTrials were considered successful if the contrast agent were distributed evenly and consistently throughout experimental sample and intercellular boundaries in cell clusters were detectable via a Sobel operator

ISSN: 1746-4811