Digital micrograph version 3.21 gms 3

The cryo-transmission electron microscopy (Cryo-TEM) measurements were performed on a JEOL JEM-2200FS electron microscope (JEOL, Freising, Germany) operating at 200 kV acceleration voltage and equipped with an “OneView” CMOS camera (Gatan, Pleasanton, CA, USA). 3 μL of a sample containing Blue at a concentration of 10 mM and DTAB at a concentration of 30 mM in an aqueous NaHCO₃/Na₂CO₃ buffer (pH = 10.5, ionic strength I ≈ 0.25 M) were deposited on the surface of a lacey carbon film coated grid (200 Mesh, Cu, Science Services GmbH, Munich, Germany) and vitrified by a Leica blotting and plunging device operating at room temperature (Leica EM GP, Leica Mikrosysteme Vertrieb GmbH, Wetzlar, Germany). The samples were plunged into liquid ethane, which was cooled with liquid nitrogen to achieve sufficiently fast cooling and freezing without formation of ice crystals. Afterwards the sample was transferred into a cryo transfer and tomography holder (Fischione, Model 2550, E.A. Fischione Instruments, Pittsburgh, PA, USA). The images captured were afterwards processed with a digital imaging processing program (Digital Micrograph®, Version 3.21, GMS 3, Gatan, Pleasanton, CA, USA).

By cryo-TEM, the structures formed by pure DOPG and DOPG with the highest glycyrrhizin amount of 50 mol% prepared in D₂O-based buffer were visualized. For imaging, a JEOL JEM-2200FS electron microscope (JEOL, Freising, Germany) equipped with a cold field emission electron gun was used. The sample was applied to a lacey carbon film coated grid (200 Mesh, Cu, Science Services GmbH, Munich, Germany) and vitrified by a Leica blotting and plunging device operated at room temperature (≈25 ${}^{\circ }$ C) (Leica EM GP, Leica Mikrosysteme Vertrieb GmbH, Wetzlar, Germany). The samples were plunged into liquid ethane, which was cooled with liquid nitrogen to achieve sufficiently fast cooling and freezing without formation of ice crystals. After freezing, the grids were transferred to a cryo transfer and tomography holder (Fischione, Model 2550, E.A. Fischione Instruments, Pittsburgh, PA, USA). The microscope was operated at an acceleration voltage of 200 kV and the images were recorded digitally by a bottom mounted camera (Gatan OneView, Gatan, Pleasanton, CA, USA). The images were afterwards processed with a digital imaging processing program (Digital Micrograph^®, Version 3.21, GMS 3, Gatan, Pleasanton, CA, USA).