Figure 12

From: Digital Signal Processing and Control for the Study of Gene Networks

Figure 12

(A) Intracellular protein levels can be controlled using light by modulating protein production and degradation. Targeted time-varying protein levels in living cells are achieved using real-time fluorescent reporter imaging and in silico feedback control. (B) Desired or “reference” fluorescence intensity at time n is denoted as r(n). e(n) is the difference or “error” between r(n) and measured fluorescence intensity value x(n) at time n. Upon receiving error signal e(n), the controller uses this error and a control algorithm, such as the PID (proportional-integral-derivative) control, to compute control signal c(n), which is the intensity of light given to the cell.