Fig. 1: Design and biological validation of the Biodome.
a The borosilicate glass culture vessel, termed the Biodome, containing 5mL RPMI 1640 media. T-25 gas permeable flask caps were allowed to rest over the inlet and outlet of the vessel while in an incubator. b Placement of the Biodome during VOC sampling shows the glass vessel is fully submerged in beads at 37 °C. Also shown is the interface between the Biodome, thermal desorption tube (TDT), and TDT adapter. A sterile rubber stopper and PTFE tape are used to create an airtight seal at the interface between the TDT and the adapter. c 3D rendering showing the major components of the gas flow system including the hydrocarbon trap, flow meter, sterile filter, tubing, Biodome, TDT adapter, and TDT sampling tube. The compressed gas cylinder is not shown. d Schematic showing relevant dimensions (in mm; OD) for the Biodome culture vessel. e Representative two-dimensional gas chromatography chromatogram spanning 400–2200 seconds in the first dimension and 0.5-2 seconds in the second dimension, following 24 hours of sampling SK-OV-3 ovarian adenocarcinoma cells. Fluid modeling in ANSYSTM demonstrates f laminar flow conditions are maintained at flow rates ≤20 mL/min (TDT adapter insert included) and g gauge pressure and h velocity changes due to the inflowing gas are negligible at roughly half the Biodome height, limiting turbulent interactions with the surface of the cell culture media. i Live/dead assay images in the Biodome show viability across 0.5–4 days. A T-75 flask at t = 0 (24 hours post seeding) is shown for reference. j Independent live-dead assays were performed using NucBlueTM (Hoechst 33342) and NucGreenTM ReadyProbesTM at 24-hour intervals, with live percentages estimated from 10 independent regions of the T-75 or Biodome culture vessels. Error bars represent standard error of the mean. No statistically significant differences in cell viability are observed using a two-sided t-test, demonstrating equivalence as compared to standard culture vessels. Scale bar = 100 µm. k Custom imaging tray was designed in SolidWorks® 2019 and 3D printed to allow imaging using a Leica DMi8. l-n Typical SK-OV-3 morphology was isualized using fluorescent imaging and a live actin tracking stain (green color), Hoechst 33342 (blue color; live stain), and NucGreen (red color; dead stain), and no differences are observed using different culture vessels and growth environments. All brightfield and fluorescent images were taken using cells at passage <10. Scale bar = 50 µm.
