title: Quantification of plasmid loss in Escherichia coli cells by use of flow cytometry.
abstract: A method was developed to study plasmid stability in Escherichia coli cells, which utilised the high speed analysis properties of flow cytometry. To discriminate between plasmid-harbouring cells and plasmid-free cells a plasmid-encoded Lac repressor protein was used to regulate the expression of a chromosomally inserted green fluorescent protein gene in the host cells. Flow cytometric analysis enabled detection and quantification of plasmid-free cells due to their green fluorescent phenotype. The reported system offers real-time analysis in combination with a very low detection level of plasmid loss in bacterial populations. This could be useful in future investigations of plasmid stability and population selection in bacterial communities.
authors.affiliation: Department of General Microbiology, University of Copenhagen, Sølvgade 83H, 1307 Copenhagen K, Denmark.
authors.forename: Martin Iain
authors.initials: MI
authors.lastname: Bahl
authors.forename: Søren Johannes
authors.initials: SJ
authors.lastname: Sørensen
authors.forename: Lars
authors.initials: L
authors.lastname: Hestbjerg Hansen
mesh_terms: D015169:Colony Count, Microbial; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development; D005434:Flow Cytometry; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics; D010957:Plasmids / Q000032:analysis*; D012097:Repressor Proteins
chemical_list: D008164:Luminescent Proteins; D012097:Repressor Proteins; D049452:Green Fluorescent Proteins