From 2007.igem.org

The Tri-stable Toggle Switch project was performed by Brown iGEM2006 team, but we need to adapt this to our needs.

Trigger

The main part of system is simple trigger, containing two repressors and to promotors. Each repressor inhibit another repressor synthesis.

Concentration inhibitors x and y describes the next system equations.

Here the constants D, K, n and r are used to describe the promoter strength and inhibition efficiency.