The University of Iowa

E. coli Derivatives

As addressed by the NIH Guidelines for Research Involving Recombinant DNA Molecules (NIH Guidelines), particular research with E. coli K-12 derivatives is exempt from the requirements of the NIH Guidelines.  

Ancestral E. coli K-12 

Strain Designation

Origin or Collection


Stanford Strain

679 Stanford strain
WG1 Wisconsin strain

E. coli K-12 Derivatives

Strain Designation Origin or Collection Strain Designation Origin or Collection
5K Lab strain JM83 Lab strain
58-161 Lab strain JM101 Lab strain
AB284 Lab strain MB408 Lab strain
AB311 Lab strain P678 Lab strain
AG1 Lab strain PA 309 Lab strain
C600 Lab strain SURE Lab strain
Cavalli Hfr Lab strain TG1 Lab strain
DH1 Lab strain W208 Lab strain
Dh5a Lab strain W945 Lab strain
DP50 Lab strain W1485 Lab strain
EMG2 Lab strain W3110 Lab strain
H1443 Lab strain WA704 Lab strain
HB101 Lab strain XL1-Blue Stratagene
Hfr3000 Lab strain XLOLR Stratagene
Hfr 3000 X74 Lab strain Y10 Lab Strain
HMS 174 Novegen YN2980 Lab Strain
JC9387 Lab strain    

For additional strains and information regarding K-12 derivatives please go to the following website:

NOTE: E. coli Laboratory Strains NOT Derived from K-12

The following E. coli laboratory strains are not derived from K-12 and therefore any research utilizing these strains is not exempt from the NIH Guidelines.

Strain Designation Origin or Collection
B Laboratory strain
B-3 Laboratory strain
BL21 Novagen
B/R  Laboratory strain
C Laboratory strain
TOPP Stratagene


Kuhnert, P., J. Nicolet, J. Frey.  1995.  Rapid and accurate identification of Escherichia coli K-12 strains.  Applied and Environmental Microbiology.  61:4135-4139.