This worked for me and it’s relatively easy to try. Transform many different cell strains with the offending plasmid. Here’s a list of cell strains available in our lab and their respective genotypes:

DH5alpha F’ /endA1 hsdR17 (rK- mK+) glnV44 thi-1 recA1 gyrA (Nalr) relA1 delta(LacIZYA-argF) U169 deoR (phi80dlac delta(lacZ)M15)

SURE

JM109

GM48 F- thr leu thi lacY galK galT ara fhuA tsx dam dcm glnV44

TOPP1-TOPP6

BL21 (DE3) F- ompT gal [dcm] [lon] hsdSB (rB- mB-; an E. coli B strain) with DE3, a lambda prophage carrying the T7 RNA polymerase gene

BL21 pLys

W3110

NM522

N4830-1

HB101 F- delta(gpt-proA)62 leuB6 glnv44 ara-14 galK2 lacY1 delta(mcrC-mrr) rpsL20 (Strr) xl-5 mtl-1 recA13

BL21 SI

(Most of this information came from the New England Biolabs catalogue)