CGSC Strain#: 6818
Strain Designation: DH20      Source of Strain: D. Hanahan
Sex: F' Episome/Plasmid: F128-18
   Plasmid Markers/Mutations: lacIp-4000(lacI^Q)
   Plasmid Comment: This F-prime came from the strain X91, which has an F128-10 derivative designated F128-17. F128-18 and F128-17 are probably the same F-prime.
Chromosomal Markers: glnX44(AS), λ^-, rfbC1, gyrA96(NalR), recA1, relA1, endA1, spoT1, thiE1, hsdR17
Strain Comments:

• This F-prime comes from the strain X91, which carries a derivative of F128-10 that was designated F128-17. F128-17 and F128-18 are probably the same F-prime, extending from ( proB-lac) and carrying lacIp-4000(lacI^Q).
• glnX44(AS)-- Mutation is a C to T transition at nucleotide 34 (3rd position of the anticodon)
• gyrA96(NalR)-- resistant to 200ug/ml nalidixic acid
• gyrA96(NalR)-- GAC to AAC at codon 87
• recA1-- : Missense mutation, altered isoelectric point. Sequenced: G to A for Nuc. 720 (Gly 160 Asp).
• endA1-- G to A transition mutation resulting in E208K amino acid substitution.
• spoT1-- In addition to the 6bp insertion, there is a C to T transition resulting in an H257Y substitution.
• glnX44(AS) was formerly called su⁺_II
• glnX44(AS) was formerly called supE44
• glnX44(AS) was formerly called glnV44
• gyrA96(NalR) was formerly called
• rfbC1 was formerly called rfbD1
• thiE1 was formerly called thi-1
• = good miniprep dsDNA quality
• AS = amber(UAG) suppressor
• NalR = Nalidix.acidResist.

References:

• Hanahan, D. 1983. Studies on transformation of Escherichia coli with plasmids. J.Mol.Biol. 166:557-580