Figure 8
The optimal inhibition strategy depends upon the diffusive time scale, measured by the Peclet number. (a) A 12 ml culture bag of initial media height h 0 = 0.33 mm (corresponding to 1 ml culture), (b) a 24-well-plate well of initial media height h 0 = 1 mm (corresponding to 0.2 ml culture) and (c) a 24-well-plate well of initial media height h 0 = 5 mm (corresponding to 1 ml culture). The diffusivity is D = 6.5 × 10−11 m2/second, the cell population is assumed constant at X = 105, and the secretion rate is r ϕ  = 1.94 × 10−6 pg/cell/day. (d) Change of dilution Peclet number with time for various initial media heights in a 24-well-plate well. Dashed lines represent the dilution Peclet number for an inhibitory signal of diffusivity 2D, and solid lines represent the dilution Peclet number for an inhibitory signal of diffusivity D, where D = 6.5 × 10−11 m2/second.