Ecoli Strain for protein expression

VernaF7449 vernaf7449 at
Fri Aug 4 12:20:05 EST 1995

Pharmacia recommends BL21 as a protease deficient host strain. The
genotype is opmT (outer membrane protease T). BL21 is a difficult cell
line to transform, however. Pharmacia does not sell this cell line by
itself (however, lyophilized BL21 cells are now supplied with the pGEX
vector). Novagen sells various BL21 strains.
A note on XL1-Blue and other rec A1 host cells (like DH5 alpha) - these
host cells can cause rearrangement or deletions of some plasmids, so
Pharmacia does not recommend these cell lines for transformation.

Verna Frasca, Ph.D.
Pharmacia Biotech, Technical Specialist

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