Team:Macquarie Australia/WetLab/Protocols/Ligation

Composite Part Ligation

The assembly of composite parts from two existing BioBricks i.e. BioBrick plasmid A (parent vector) and BioBrick plasmid B (gene to be inserted) was performed through a restriction digest/ligation protocol.

• 200ng of each BioBrick plasmid was digested as follows: Plasmid BioBrick A with NEB restriction enzymes SpeI and PstI; plasmid BioBrick B with XbaI and PstI, according to supplier protocol. (1hr @37°C, then 20mins @80°C).
• 1µL of Fast alkaline phosphatase (Thermo Scientific) was added to reaction tube of plasmid BioBrick A to dephosphorylate the gene fragments and prevent re-ligation of the parent vector. Reaction tubes were incubated at 37°C for 60 mins, followed by a deactivation step at 80°C for 20 mins.
• Ligation was then performed with an insert to vector molar ratio of 3:1. 1µL of T4 ligase (NEB) was added to the mix for ligation, according to supplier protocol. Ligation reactions were performed at 37°C for 60 mins and kept on ice for transformation into chemical competent cells.