Axio image m1 microscope

Engineered constructs as well as native auricular cartilage tissue samples were fixed in 4% paraformaldehyde (in 0.1 M PBS, pH 7.2) for 24 hours, dehydrated in graded ethanol solutions and embedded in paraffin at 65°C. Thin (5 µm thick) sections were cut and mounted on Superfrost slides (Fisher Scientific, Mississauga, Canada) and dried for 24 hours at 37°C. Sections were stained with safranin-O (proteoglycan stain), Weigert's resorcin-fuchsin (elastin/elastic fiber stain) or hematoxylin & eosin (H&E; general connective tissue stain). Stained sections were examined by light microscopy using a Zeiss Axio-Image M1 microscope (Göttingen, Germany).

To investigate vegetative hyphae and sexual structures, S. macrospora strains were grown on solid SWG medium covered with a piece of cellophane (0.5 cm × 0.5 cm) over 2 to 9 days and documented with an AxioImage M1 microscope (Zeiss, Jena, Germany) using differential-interference contrast (DIC) or a VHX-500F Digital Microscope (Keyence, Neu-Isenburg, Germany). Images were captured with a Photometrix CoolSNAP HQ camera (Roper Scientific, Photometrics, Tucson, AZ, USA). Image processing was done using ZEISS ZEN Digital Imaging (version 2.3; Zeiss, Jena, Germany) and the Affinity Publisher software (version 1.9.2.1035, Serif (Europe) Ltd., Nottingham, UK, https://affinity.serif.com/de/publisher/; accessed on 1 March 2021).
For fluorescence microscopic analyses, S. macrospora strains were grown on selective BMM medium on top of cellophane sheets or on BMM-covered glass slides for 24 h at 27 °C. For the detection of the EGFP signal Chroma filter set 49002 (exciter ET470/40x, ET525/50m, beamsplitter T495lpxr) and for TagRFP-T/tdTomato Chroma filter set 49005 (exciter ET545/30x, emitter ET620/60m and beamsplitter T570LP) was used.