Figure 2: Dynamic Sampling Platform (DSP) ESI-MS setup for direct 2D cell culture analysis. The DSP, is contained in a fluidic package which allows for continuous sample treatment in a tangential flow mass exchanger orientation (right inset image). DSP, in the package, is positioned so that the ESI emitter is directly in front of the MS inlet. The DSP is connected to the sampling interface, which consists of a 50 μL syringe, union, and sampling inlet. Localized sampling is carried out by positioning the inlet directly above the bottom of the cell culture, in close proximity to the cells, while bulk sampling is carried out by submerging the capillary just below the media surface (bottom inset image).