...to use in an experiment. E. coli strains for propagating plasmids E. coli are gram-negative, rod shaped...Addgene blog posts relating to common E. coli lab strains and E. coli strains specialized for protein expression... with Plasmids Introduction Types of Plasmids E. coli strains for propagating plasmids Antibiotics commonly...For instance, most plasmids are replicated in E. coli and are relatively small (∼3000 - 6000 basepairs.... When a plasmid exists extrachromosomally in E. coli , it is replicated independently and segregated ...many different naturally occurring strains of E. coli , some of which are deadly to humans. The majority...majority of all common, commercial lab strains of E. coli used today are descended from two individual isolates...