Fig. 2

Trimming, approaching and sensitivity to charging in en bloc and MR embedded samples. A, B, K, L Polymerized samples on pins observed under the stereomicroscope before they were sputter gold coated. Colloidal silver (cs) was applied around the base of the sample in B. C–F, M–P Side views of samples visualized in the classical SEM mode using SE. C, D, M, N Measuring the length of the material above the ROI (white arrow) that has to be trimmed off. These values were estimated in en bloc embedded samples (C, M). E, F, O, P Trimmed samples. Only a few sections of outer resin were trimmed in P. A classical pyramid was made in E and O. G–J, Q–T Top views of samples visualized in the SBF-SEM mode using BSE. G, H, Q, R Overview during approaching. I, J, S, T Images of embedded tissue after a few sections were cut. All observed in high vacuum. Yellow arrowheads mark charging (white regions). Samples: A–J Trunk fragment of O. cincta; ROI: an appendicular organ (collophore) in the middle of the body. K–T Roe of O. latipes; ROI: full width from the top. cs, colloidal silver; white arrows mark the ROI; yellow arrowheads mark charging. Scale bars: A–D, K–N, 1 mm; E–H, O–R, 500 μm; I, J, S, T, 30 μm