Acetone

Hemocytes were fixed in a mixture of 2% paraformaldehyde and 2.5% glutaraldehyde (Thermo Fisher Scientific, Frederick, MD, USA) in a culture medium. Postfixation was carried out with 1% osmium tetroxide (Sigma-Aldrich, St. Louis, MO, USA) in 0.05 M cacodylate buffer (Vekton, Russian Federation), pH 7.4, using a low-temperature automatic water replacement system Leica EM AFS2 (Leica Microsystems, Germany).
The samples were infiltrated with epoxy resin (Agar Scientific Ltd, UK) / acetone (Vekton, Russian Federation) (1:3) for 30 min, followed by resin / acetone (1:2) for 30 min, followed by 1 h with resin / acetone (1:1) under room temperature. The samples were then transferred into the 100% resin; the polymerization was carried out over 24 h at +60°C. Resin blocks were carefully trimmed using a Leica EM UC7 trimmer. Ultrathin slices were collected on the mesh copper grids coated by carbon film (SPI Supplies, West Chester, PA, USA), post-stained with 1% uranyl acetate (Agar Scientific Ltd, UK) in water for 5 min, and with a lead solution for 7 min, and washed in distilled water. The material was then analyzed with a transmission electron microscope JEM– 1400 (Jeol, Japan).

1-Dodecanthiol (DDT, 98%) was obtained from Acros Organics; Zinc stearate (65%), Zinc oxide (99%) and Indium (III) acetate (In(Ac)₃, 98%), Silver (I) nitrate (AgNO₃, ≥99.5%), Oleic acid (OA, 90%), 1-Octadecene (ODE, 90%), Oleylamine (OlAm, 70%), 2-Ethylhexanoic acid (99%), Thiourea (99%), Triethyleneglycol dimethylether (98%), L-cysteine hydrochloride monohydrate (98%), Potassium hydroxide (KOH, 90%) were purchased from Sigma Aldrich (Saint Petersburg, Russian Federation). Organic cyanine dyes: 3,3′-diethylthiacarbocyanine iodide (Cy3) (95%) and 3,3′-diethylthiadicarbocyanine iodide (Cy5) (98%) were purchased from Sigma-Aldrich. Solvents: Isopropanol (99.8%), acetone (99.75%), and chloroform (99.9%) were obtained from Vekton (Saint Petersburg, Russian Federation). All chemicals were used without further purification. Ultrapure water (Milli-Q) was used throughout the experiments.

The crab α-chitin (Biolog Heppe GmbH, Landsberg, Germany) used had a weight average molecular weight (M_w) of 5.86 × 10⁵ and dispersity (Ð) of 4.3. A degree of acetylation of 0.98 was calculated using solid-state cross-polarization magic angle spinning carbon-13 nuclear magnetic resonance (¹³C CP-MAS NMR) spectroscopy. Phosphoric acid 85 wt.% in H₂O (99.99% trace metals basis), acetone (purity of 99.7%) and DMAc (purity of 99.95%) were supplied by Vekton (St. Petersburg, Russia). Lithium chloride (purity of 99%) was supplied by Sigma-Aldrich (St. Louis, MO, USA).