The dye used consists of Rhodamine B (RhB, Exciton, Lockbourne, USA) to stain proteins, and CalciFluor white (CFW, ID: 18909, 1 g/L with 0.5 g/L Evans blue, liquid form, Merck, Rahway, USA) to stain polysaccharides. A solution of RhB in ethanol was first prepared by dissolving 50 mg of RhB in 1.5 mL of pure ethanol. The mixture was vortexed to dissolve all dye. Then, in 1.5 mL of PEG-200, 15 μL of the RhB solution and 50 μL of the liquid CFW solution were dissolved. A droplet of this dye was placed on a 125 μm thick glass slide, on which a cut frozen sample was placed. This was cut either with a razor blade, or microtome. The microtome cut samples were first attached to a metal cooling head using Tissue-Tek® O.C.T. Compound (Sakura Finetek, USA) medium. They were then cut using a cryomicrotome (Cryostar NX70, Thermo Fischer Scientific, Germany) resulting in slices of 50 ± 5 μm thickness. The head temperature was -12 °C and the blade temperature was -10 °C. The thin slices were then transferred to the glass slide.