I am trying to choose a strain for expression of a plasmid. Which one would be better?
The answer is going to depend upon some various things.
First of all, when you write BL21 do you really mean BL21 or do you mean BL21(DE3). The two strains are different. Many people use BL21 as shorthand for the DE3 strain, but it is in fact different.
Secondly, what is your expression vector, or more precisely what promoter is being used. BL21(DE3) is designed to permit expression from plasmids with the T7 promoter, such as the pETxx series of plasmids. If you are using one of those plasmids, then it will not work in HB101 and you need to use BL21(DE3) or something similar that provides T7 polymerase.
On the other hand if you are using a plasmid with a different promoter, then you probably don't want to use BL21(DE3) because expressing the T7 polymerase can have impacts on the cellular physiology.
Additionally HB101 does not adequately regulate any promoters based on lac, in other words any promoters that require IPTG induction. Generally HB101 was designed as a cloning strain and not an expression strain, although it can be used for expression in some circumstances.
So the choice of strains depends upon the expression plasmid, the mode of regulation of that plasmid and to some degree the protein you are trying to express. If you provide more specifics you might get a more detailed answer.
- Badges
- Science topic
- Similar topics
- Biological Science
- Molecular Biology
- Molecular Biological Techniques