The first article in this series was an introduction to Turing pattern formation, it briefly covered the theory behind the formula, where it is generally applied and experimental proof confirming the theory. In the second article, I explained briefly the concept of genetic circuits; comparing genetics to electronic circuits, and a brief expla natio n of the mechanism of a simple genetic toggle switch circuit. Here, I am going to bring these two branches of science together to try to explain how to construct a genetic circuit that produces patterns in Turing instability fashion. This is a theoretical exercise, we assume that the biological parts chosen here behave exactly as we want them to behave, which is not necessarily true all the time. I will not cover biological details behind the choice of promoters and genes, instead, we will have an engineering mentality of picking components from the shelf approach. As we will see later, it works in the real world Design From First Principl