Figure 2

The Vitrocell mammalian exposure module (6/4 CF Stainless). [A] Top view of the module base (lid removed) looking into the four separated wells where cell culture inserts would usually sit and be exposed to smoke, but where four identical QCM units have been installed, 1–4 (left-right). [B] A schematic cross-section of the module base and lid depicting how smoke is delivered to cell culture inserts/QCM. This illustration shows a very slight difference in the heights of the crystal surface and a typical cell exposed on a porous membrane; in our set-up the QCM is 1.5 mm higher than an exposed cell surface would be. However, the trumpet height can (and should) be adjusted to compensate for this when exposing cells and QCMs concurrently so that the gap distance is the same (2 mm in this case between crystal and trumpet).