File:Level 1 GoldenGate.jpg

Level 0 parts can be combined in a Golden Gate dig-lig reaction with the appropriate level one acceptor to create a level one construct that will usually consist of a complete transcriptional unit. The BsaI sites are convergent on each level 0 part and divergent on the level 1 acceptor, therefore will be removed by the process of cloning and will not exist in the assembled level 1 construct. The assembly product has no restriction sites for Bsa1 but is flanked by inverted, convergently orientated BpiI sites. The Level one acceptor must be chosen according to which position the construct will occupy in the prospective level two construct.