Sudden stop in recombinant protein expression in BL21?

Raheleh Tooyserkani @Raheleh-Tooyserkani

09 February 2015 1 4K Report

I have cloned a 25KD fragment in pet32a and I got recombinant expression in BL21. The yield of expression was very good, but suddenly it stopped expressing!I tried transforming new BL21 bacteria with purified plasmid in the same condition and I got no expression anymore! I want know is there any problem with my bacteria,culture conditions or...!

Dominique Liger

Hi there,

Plasmid transformed BL21 strains are genetically unstable so the best is to start from fresh transformation every time you want to produce your protein of interest.

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