Strain: AR58

Genotype: sup⁰ galK2 galE::Tn10 (lcI857 DH1 bio^- uvrB kil^- cIII^-) Str^r

Strain: AR120

Genotype: sup⁰ galK2 nad::Tn10 (Tet^r) (lcI⁺ ind⁺ pL-lacZfusion) Str^r

Strain: ASI^b

Genotype: endA1 thi-1 hsdR17(_rK-_mK+) supE44 (lcI⁺)

Strain: BNN102^b

Genotype: C600 hflA150 chr::Tn10 mcrA1 mcrB

Strain: BW313^c

Genotype: Hfr lysA^- dut ung thi-1 recA spoT1

Strain: C600

Genotype: thi-1 thr-1 leuB6 lacY1 tonA21 supE44 mcrA

Strain: CJ236^c

Genotype: dut1 ung1 thi-1 relA1/pCJ105 (Cm^r)

Strain: DH1

Genotype: recA1 endA1 thi-1 hsdR17 supE44 gyrA96 (Na1^r) relA1

Strain: DH5aF'

Genotype: F'/endA1 hsdR17(r_K-m_K+) supE44 thi-1 recA1 gyrA (Na1^r) relA1 D(lacZYA-argF)_U169(m80lacZDM15)

Strain: DK1

Genotype: hsdR2 hsdM+ hsdS+ araD139 D(ara-leu)₇₆₉₇D(lac)_X74 galU galK rpsL (Str^r) mcrA mcrB1 D(srl-recA)₃₀₆

Strain: ER1451

Genotype: F' traD36 proAB lacl^q D(lacZ)M15/endA gyrA96 thi-1 hsdR2 (or hsdR17) supE44 D(lac-proAB) mcrB1 mcrA

Strain: HB101^e

Genotype: D(gpt-proA)62 leuB6 thi-1 lacY1 hsdS_B20 recA rpsL20 (Str^r) ara-14 galK2 xyl-5 mtl-1 supE44 mcrB_B

Strain: JM101^f

Genotype: F' traD36 proA+ proB+ lacl^q lacZDM15/supE thi D(lac-proAB)

Strain: JM105^f

Genotype: F' traD36 proA+ proB+ lacl^q lacZDM15/D(lac-pro)_X111 thi rpsL (Str^r) endA sbcB supE hsdR

Strain: JM107^f

Genotype: F' traD36 proA+ proB+ lacl^q lacZDM15/endA1 gyrA96 (Nal^r) thi hsdR17 supE44 relA1 D(lac-proAB) mcrA

Strain: JM109^g

Genotype: F' traD36 proA+ proB+ lacl^q lacZDM15/recA1 endA1 gyrA96 (Nal^r) thi hsdR17 supE44 relA1 D(lac-proAB) mcrA

Strain: K38

Genotype: HfrC (l)

Strain: KM392

Genotype: hsdR514(_rK-_mK+) supE44 supF58lacY galK2 galT22 metB1 trp55 mcrA Dlac_U169 proC::Tn5

Strain: LE392

Genotype: hsdR514(_rK-_mK+) supE44 supF58lacY galK2 galT22 metB1 trp55 mcrA

Strain: MC1061

Genotype: hsdR2 hsdM+ hsdS+ araD139 D(ara-leu)₇₆₉₇D(lac)_X74 galE15 galK16 rpsL (Str^r) mcrA mcrB1

Strain: MM294

Genotype: endA thiA hsdR17 supE44

Strain: NM539^h

Genotype: supF hsdR (P2cox3)

Strain: P2392

Genotype: hsdR514 (r_K^-m_K⁺ ) supE44 supF58 lacY galK2 galT22 metB trp55 mcrA (P2)

Strain: PR722

Genotype: F' D(lacIZ)_E65 pro⁺/proC::Tn5 D(lacIZYA)_U169 hsdS20 ara-14 galK2 rpsL20 (Str^r) xyl-5 mtl-1 supE44 leu

Strain: Q359

Genotype: hsdR^- hsdM⁺ supE tonA (j80r) (P2)

Strain: RR1

Genotype: D(gpt-proA)62 leuB6 thi-1 lacY1 hsdS_B20 rpsL20 (Str^r) ara-14 galK2 xyl-5 mtl-1 supE44 mcrB_B

Strain: Y1088^h

Genotype: supE supF metB trpR hsdR^- hsdM⁺ tonA21 strA Dlac_U169 mcrA proC::Tn5/pMC9

Strain: Y1089^h

Genotype: Dlac_U169 proA⁺ D(lon) araD139 strA hflA150 chr::Tn10/pMC9

Strain: Y1090^h

Genotype: Dlac_U169 proA⁺ D(lon) araD139 strA supF trpC22::Tn10 mcrA/pMC9

^a The original E.coli K-12 strain was an F+l lysogen, but most K-12 derivatives in common use have been cured of the
F factor and prophage and these are indicated only when present.
All other genes in these strains are presumed to be wild-type except for the genotype markers noted in the second column.

^b AS1 is also known as MM294cI+ , BNN102 is also known as C600 hflA.

^c Both CJ236 and BW313 are commonly used in oligonucleotide-directed mutagenesis, pCJ105, the plasmid CJ236 carries, is not relevant for this application.

^d Three strains are in circulation. DH5 is a derivative of DH1 that transforms at higher efficiency. DH5a and DH5aF' are derivatives that carry a deletion of the lac operon and f80 prophage that directs synthesis of the omega fragment of b-galactosidase. DH5aF' carries an F' factor as well. DH5a and DH5aF' are proprietary strains and the cells are prepared in some way that allows them to be transformed with slightly higher efficiency than DH5.

^e In this strain, the area of the chromosome that contains the hsd genes was derived from the related B-strain of E.coli.

^f The continued presence of the F' factor in JM strains can be insured by starting cultures only from single colonies grown on minimal plates that do not contain proline. These strains encode the omega fragment of lacZ and are frequently used with vectors that direct the synthesis of the lacZ alpha fragment. These strains are frequently used with M13 vectors for DNA sequencing.

^g It is not known whether this strain has markers other than those listed.

^h pMC9, the plasmid in the Y strains listed here, directs the synthesis of large amounts of lac repressor It also confers resistance to tetracycline and ampicillin (Miller et al., 1984, EMBO.J.3:3117-3121).