Is it dangerous to use the StabyExpress™ kit due to the poison and antidote genes or proteins?
Since the StabyExpress™ kit uses a natural bacterial poison (CcdB), one might fear that the poison could contaminate products extracted from the bacteria and could possibly be toxic for those using these products. However, all E. coli strains currently used in bacterial fermentation processes contain several poison-antidote operons in their chromosome. The CcdB poison is not toxic in mammalian cells. Finally, the poison and/or antidote proteins (CcdB and CcdA) are very small (8.7 and 11.7 kDa, respectively), and can therefore be easily removed from the protein extract during downstream purification (most proteins of interest have much higher molecular weights).
