How much L-arabinose should I use to induce expression with the pBAD expression system?
While the amount of L-arabinose can vary depending on your expression experiment, we suggest performing a pilot expression experiment with varying amounts of L-arabinose from 0.00002% to 0.2%.
Should I use TOP10 cells or the LMG194 E. coli strain you offer for expression with my pBAD system?
Top10
Advantages:
- Saves time, can go directly from cloning to expression.
- The glycerol stock is more stable because these strains are endA- and recA-.
Disdvantages:
- This strain is not protease-deficient. Therefore, the protein may be degraded.
LMG194
Advantages:
- Grows well in minimal media, except M9.
-Have to transform the plasmid into the cells just for expression.
-RM medium with glucose to ensure low basal level of protein.
Disadvantages:
- Not protease-deficient. Therefore, the protein may be degraded.
- The glycerol stock may not be stable because this cell strain is not recA- or endA-.
What competent cells do you recommend I use for expression with my pBAD expression system?
We recommend using a competent cell strain that is araBADC- and araEFGH+, allowing transportation of L-arabinose, but not metabolizing it. This is important for expression studies, as the level of L-arabinose will be constant inside the cell and will not decrease over time. We offer our TOP10 competent cells, or our LMG194 E. coli strain.
Can you tell me the sequence of primers that can be used in pBAD vectors to sequence my gene of interest?
The pBAD vectors contain a forward and reverse pBAD primer flanking the gene of interest. The sequences are as follows:
pBAD forward primer:
5'-ATGCCATAGCATTTTTATCC-3'
pBAD reverse primer:
5'-GATTTAATCTGTATCAGG-3'
Do you have a list of the cap colors for the pBAD vectors?
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PubMed ID:11553807
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