Axio imager optical microscope

Formalin-fixed, paraffin-embedded tissue sections were deparaffinised and rehydrated. Heat-induced antigen retrieval was performed using a 10 mM sodium citrate buffer with 0.05% Tween-20 (pH 6.0) at 95°C for 15–20 min. Hydrogen peroxidase block was performed for 15 min followed by further incubation with blocking buffer for 1 h. Abcam protein block was applied for 10 min and then sections were incubated in primary antibody at 4°C overnight in a wet chamber. Sections were incubated with biotinylated goat anti-polyvalent for 10 min and covered with streptavidin peroxidase for a further 10 min. 3, 3′-diaminobenzidine (DAB) chromogen (HRP/DAB (ABC) Detection Kit, Abcam) was added to DAB substrate, applied to sections, and incubated for 1–3 min. Haematoxylin counterstain was performed, washed in tap water and slides dipped into Scott's Tap Water Substitute. Sections were dehydrated and mounted using DPX (Fischer Scientific). Slides were imaged with an Axio Imager optical microscope (ZEISS).

The flax yarn diameters, as well as the fragment lengths, were measured by using a ZEISS Axio Imager optical microscope (Oberkochen, Germany). A morphological investigation of scCO₂ treated and untreated flax yarns was carried out using a field-emission gun scanning electron microscope (FE-SEM) Zeiss Auriga. All specimens were sputter-coated with chromium prior to FE-SEM observation.