The idea of our circuit can be simply represented by this picture:

Basically, our aim is the biological design of a decoder that only expresses the codified genetic information when, where and which is desired by the user. The election of the output to decode, is achieved by the combination of two kinds of light: red and blue. Two inputs are given at times t₁ and t₂ with the possibility of election between red or blue light. This, this would be the truth table of our circuit:

The biological components that allow us this implementation in living organisms are two switches, two recombinases and a library of different binding domains. All those elements have been coordinated in this cascade of three different levels:

In order to predict the results of our biological circuit, we must be able to express its performance in numerical terms. Using Mass Action Kinetics we got our deterministic model with all its equations describing interactions between all elements of the circuit.