Haynes:TypeIIS Assembly: Difference between revisions
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| <font size= | | <font size=3>'''Use PCR to prepare the parts'''</font> | ||
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* Multiple parts can be assembled in one step. | * Multiple parts can be assembled in one step. | ||
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| [[Image:Haynes_TIIS_fig6.png|250px|Figure 6]] || Run separate 50 μL PCR reactions for each part. If you are using plasmid DNA as a template, use no more than 10 ng in order to minimize carry-over into the final bacterial transformation step. Check 10 μL of the reaction on and agarose gel. Purify the remaining 40 μL of PCR products using a Zymo clean and Concentrator kit (or similar PCR clean up kit). | | [[Image:Haynes_TIIS_fig6.png|250px|Figure 6]] || Run separate 50 μL PCR reactions for each part. If you are using plasmid DNA as a template, use no more than 10 ng in order to minimize carry-over into the final bacterial transformation step. Check 10 μL of the reaction on and agarose gel. Purify the remaining 40 μL of PCR products using a Zymo clean and Concentrator kit (or similar PCR clean up kit). | ||
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| <font size= | | <font size=3>'''Digestion/ ligation reaction'''</font> | ||
| '''Dilute the purified PCR product to 20 fmol/μL''' | | '''Dilute the purified PCR product to 20 fmol/μL''' | ||
* Measure ng/μL of the purified sample. | * Measure ng/μL of the purified sample. |
Revision as of 17:40, 19 January 2013
by Karmella Haynes, 2013
Principle: The familiar "BioBrick cloning" enzymes (i.e., EcoRI, NotI, XbaI, SpeI, PstI) are Type II restriction enzymes, which cut the sequences that they specifically bind to. The Type IIS Assembly method uses a Type IIS restriction enzyme, which binds at a specific sequence and cuts at a non-specific location exactly five base pairs away. As a result, the enzyme cleaves away its own binding site and leaves behind the most useful feature of assembly, sticky overhangs. When designed properly, Type IIS sites can be used to perform seamless assembly of parts. As an added convenience, this protocol allows cutting and ligation to occur in a single tube, as a single reaction. Thus, gel purification steps can be eliminated.
This protocol uses the Type IIS restriction enzyme BsmBI (CGTCTCn/nnnn).
Bacterial transformation
- Add total volume (10.0 μL) to 50 μL chemically competent cells (e.g., BL21) in a 2.0 mL tube.
- Incubate on ice for 2 min., heat shock at 42°C for exactly 90 sec., immediately place on ice.
- Add 800 μL sterile SOC medium.
- Grow with shaking at 37°C for 30 min.
- Pellet the cells at top speed in a microcentrifuge for 3 min. at room temp.
- Discard the supernatant. Resuspend the cells in 100 μL LB + antibiotic.
- Plate cells on pre-warmed LB agar + antibiotic. Grow overnight at 37°C.
- Quick-transormation (e.g., DH5α-Turbo) is not recommended