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amount of plasmid for transformation and fusion protein expression - (Sep/26/2010 )

hello. i just want to ask if there is an effect of too much plasmid transformed in Bl21 before protein induction of a gst-fusion protein.

What is the ideal amount of plasmid need to transform in Bl21 that may give a higher induction of protein? thank you...


Normally, every cell gets transformed with a single plasmid. Protein expression depends on your promoter, copy number of your plasmid, concentration of inducer, gene sequence etc. The concentration of the plasmid should affect only the number of colonies you get and have no effect on protein expression. I'm not sure if using an outrageous amount of plasmid will cause transformation of more than one plasmid into a single cell but I don't think that should not affect expression level.