Stability analysis of the dynamic genetic circuit at the single cell level. (a) Oscillatory region of the system at very low levels of IPTG (i = 0). Φ, Ψ, and Γ are defined in the main text. The bifurcation for bistability is at -Ψ/(Γ - Φ) = -1 (not shown in the Figure). (b) Bistability region of the system at very high levels of IPTG (i >> 1) and external AHL (a >> 1). To plot (b) we have considered a simplified model (see Methods).