Single part Gibson assembly
This is my first attempt at a simple vector + single part Gibson assembly reaction.
Set up assembly reactions on ice:
- 15 ul Gibson master mix
- 1 uL vector (V.f/V.r) (~50 ng total)
- 1 uL part (I13522 A.f/END.r) (~50 ng total)
- 3 uL water
20 ul total volume.
- Incubated 50 °C, 60 mins.
- Transformed into 50 ul DH5α competent cells
- (1 hour on ice, heat shock 1 min 42 °C, + 200 uL SOC, 37 °C shaking 1 hour, plated on LB chlor or LB tet agar plates)
- Grew plates O/N 37 °C, then left at 4 °C.
Did reactions:
- linear pSB1C3 V.f/V.r only
- linear pSB1T3 V.f/V.r only
- linear pSB1C3 V.f/V.r + I13522 A.f/END.r
- linear pSB1T3 V.f/V.r + I13522 A.f/END.r
Successful assemblies should give 'green' colonies since I13522 constituatively expresses GFP under a tetR promoter.
Result (11/06/2011):
- linear pSB1C3 only: ~ 400 colonies, ~ 50 % red (RFP) from contaminating circular parent vector.
- linear pSB1C3 + I13522: ~ 400+ colonies, ~ 50 % red (RFP), ~ 10 % green (GFP), ~ 40 % uncoloured
- Tet plates (pSB1T3 reactions) - lawn of bacteria .. bad antibiotic ?
Conclusions:
- Appears that the assembly reaction worked for pSB1C3 + I13522, although at low efficiency.
- Need to reduce amount of circular parent vector by using less template in PCR reaction of DpnI treating linear vector PCR products.
- There are many resistant colonies that don't appear to be producing GFP (ie likely to contain no I13522 part) - possible that the linear vector is able to recicularize in the reaction through production of weakly annealing sticky ends ?
- Should do a I13522 A.f/END.r only control, in case GFP colonies represent part template vector contamination.
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bbGibson assembly
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