DOULIX is a synthetic biology toolkit to design, validate and synthesize custom synthetic biology constructs. DOULIX allows you to design your custom construct by assembling standard biological parts called BIOMODULES into multipartite plasmids. You can choose from our broad collection of public BIOMODULES or create your custom sequence and assemble them into your vector of choice. DOULIX also helps you to avoid most common design flaws by guiding you through a step-by-step validation of your construct. You can then order your ready-to-use full-length construct or individual BIOMODULES to build it yourself.