BL21 (DE3) Induction

Michael J. Tuvim mtuvin at
Wed Oct 4 13:43:20 EST 1995

In article <4461n4$mfn at> "J.P. Hays" <jph5 at> writes:
>I am hoping to use E. coli BL21(DE3) (Novagen Ltd) to express a protein product
>in a pGEM vector.If anyone has any experience in using this strain of E. coli
>for protein expression and has any tips I would be very grateful.
>Thanks in advance.
>John HAYS

We use this strain. Grow the bug to OD(600nm) ~0.8,  add IPTG to 0.8 mM,
shake another 3 hours (LB with an appropriate antibiotic), harvest.

It seems BL21(DE3) really doesn't like chloramphenicol, don't know why.

We add a bit more Amp when adding IPTG (helps to retain plasmid better).

Michael Tuvim

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