Figure 4:

CRISPR/Cas9-based devices and circuits drawn using SBOL Visual 2. (a) NOR device from Gander et al.,²² in which gRNA/dCas9 complexes repress operators upstream of a promoter that regulates the production of gRNA, which in turn binds with dCas9-Mxi1 to complete implementation of a digital NOR logic device. Note the use of color coding to distinguish the _x/_y/_z gRNAs, and the dashed module boundary identifying device inputs and outputs. (b) Interconnection of three NOR devices to implement an AND circuit from Gander et al.²² Expression of green fluorescence protein (GFP) is used as output and module boundary crossings show how devices are interconnected to form a circuit.