Universal oven un110

Right after cell loading, all ports of the Organ-Disc were topped up with medium. The reservoir was attached to the Organ-Disc using double-sided adhesive tape (ARcare 90106, Adhesives Research) for a strong and permanent connection during the experiment runtime. Alternatively, we connected the reservoir reversibly by clamping a 2 mm thick layer of silicone (Sylgard 184, Dow Corning) in between the reservoir and the Organ-Disc. Silicone was mixed in a 10:1 (base: curing agent) mass ratio and cured for at least 4 h at 60 °C (Universal Oven UN110, Memmert). Finally, silicone was cut in the shape of the reservoir's bottom layer.
Prior to centrifugal media perfusion, the inner reservoir compartment was filled with medium and the Organ-Disc was spun for 30 s to flush the media channel with medium (500–1000 rpm or 11.6 g–46.4 g, respectively). Next, the Organ-Disc and reservoir were mounted on the perfusion spinner and continuous rotation under culture conditions was started. Each day, the centrifugal perfusion was stopped and the Organ-Disc was removed from the perfusion spinner. The effluent of each system was aspirated, and the cells were inspected using an inverted light microscope with a tempered enclosure at 37 °C (Leica DMi8, Leica Microsystems). Afterward, medium was refilled and centrifugal perfusion restarted.

Content of dry matter was determined by oven-drying at 105 °C [32 ] using a Universal Oven UN 110 (Memmert GmbH + Co. KG, Büchenbach, Germany). A Kjeltec auto type 1030 analyser (Tecator Co., Hoganas, Sweden) was used to determine the crude protein content. Lipids were isolated in ground samples with petroleum ether in Soxhlet apparatus (LTHS 500, Brnenská Druteva v.d., Brno, Czech Republic) and were determined gravimetrically. Fatty acid composition of breast and thigh meat samples was determined by an evaluation of their methyl ester content via gas chromatography, according to Čertík et al. [24 ], as described above.
To determine the lipid oxidation changes of breast and thigh muscles, the 2-thiobarbituric acid spectrophotometric method was used. The extent of lipid oxidation involved the measurement of thiobarbituric acid reactive substances (TBARS), as prescribed by the method of Reitznerová et al. [33 (link)]. TBARS values were measured spectrophotometrically at 532 nm (Helios α, v.4.6 Thermo Spectronic, Cambridge, UK). TBARS values were determined within 24 h after slaughter and after 7-day storage in a refrigerator (+4 °C). Results were quantified as malondialdehyde (MDA) equivalents and expressed as mg of malondialdehyde/kg of sample.

To cast PDMS onto the silicon wafer, a fluoroelastomer-based O-ring (138 mm × 2 mm FPM 75, Dichtelemente arcus, Seevetal Germany) was placed concentrically on the wafer. Both, wafer and O-ring, were clamped between two 5 mm thick polymethyl methacrylate (PMMA) plates (Oroglas cast acrylic glass, Trinseo, Berwyn, PA, USA) with the upper one featuring two ports for connecting 50 mL syringes (BD Plastipak, Becton Dickinson, Heidelberg, Germany). PDMS (Sylgard 184, Dow Corning, Wiesbaden, Germany) was mixed in a 10:1 (base:curing agent) mass ratio, degassed in a desiccator, and filled into one of the syringes connected to the PMMA plate. By slowly pulling the plunger of the other syringe, PDMS was injected into the O-ring sealed cavity on the wafer. PDMS was cured overnight at 60 °C (Universal Oven UN110, Memmert, Büchenbach, Germany). After curing, the PMMA plates were removed, and the PDMS was peeled off the wafer and cleaned with isopropanol as well as compressed nitrogen.