History & Biology

Genentech Center Conferences on the History of Molecular Biology and Biotechnology
at Cold Spring Harbor Laboratory

Meeting: 21–24 September 2014

Plasmids: History & Biology

A special meeting, entitled, Plasmids: History & Biology, was held from Sunday, September 21, to Tuesday, September 23, 2014, in the Hershey Laboratory, at Cold Spring Harbor Laboratory, New York. The meeting was hosted by the CSHL Genentech Center for the History of Molecular Biology and Biotechnology.

The CSHL Genentech Center Conferences aim to explore important themes of discovery in the biological sciences, bringing together scientists who made many of the seminal discoveries that began the field with others whose interests may include the current status of the field, the historical progress of the field, and/or the application of these techniques and approaches in biotechnology and medicine.

Organizers of the meeting were: Stanley N. Cohen, Stanford University School of Medicine; Stanley Falkow, Stanford University School of Medicine; Richard Novick, New York University; Dhruba Chattoraj, National Cancer Institute; Christopher Thomas, University of Birmingham, UK; Jan Witkowski, Cold Spring Harbor Laboratory.

The meeting featured speakers from the US and Canada, as well as Belgium, Germany, France, Mexico, Spain, Sweden, and the UK. The meeting included 25 talks and posters, on topics such as:

The nature of plasmids

  • Discoveries elucidating the nature of the extrachromosomal genetic elements
  • Plasmid structure and topology
  • Plasmid DNA replication
  • Transposition & genetic recombination
  • Plasmid-borne genes and metabolic functions

Plasmids as genetic elements expressing phenotypic properties affecting cell biology

  • Antibiotic resistance
  • Bacterial toxins and microcins: plasmids and pathogenicity
  • Interbacterial transferability
  • Stability, partitioning, post segregation lethality

Plasmids as whole systems

  • Plasmids and restriction/modification
  • Degradative functions
  • Plasmids and plants (tumorigenesis, nitrogen fixation)
  • Plasmid host range and evolution

The meeting included two special discussions: One on plasmid properties and biologically-important plasmid encoded phenotypes, and another on future directions in plasmid biology. The meeting also featured a roundtable where historians and scientists presented their views and engaged in discussion on the role of plasmids in the development and overall history of the biological sciences.


  • Dhruba Chattoraj, National Cancer Institute, Bethesda, MD
  • Stanley N. Cohen, Stanford University
  • Stanley Falkow, Stanford University
  • Richard Novick, New York University
  • Chris Thomas, University of Birmingham, UK
  • Jan Witkowski, Cold Spring Harbor Laboratory, NY


  • Peter Barth, Helsby, Cheshire UK
  • Susana Brom, Universidad Nacional Autonóma de México, Cuernavaca, Morelos Mexico
  • Ananda Chakrabarty, University of Illinois
  • Mike Chandler, Université Sabatier, Toulouse, France
  • Dhruba Chattoraj, National Cancer Institute, Bethesda, MD
  • Don Clewell, University of Michigan, Ann Arbor, MI
  • Stanley N. Cohen, Stanford University
  • Fernando de la Cruz, Universidad de Cantabria, Spain
  • R. Curtiss III, Arizona State University, Tempe, AZ
  • Julian Davies, University of British Columbia, Canada
  • Stanley Falkow, Stanford University
  • Laura Frost, University of Alberta, Edmonton, Alberta, Canada
  • Barbara Funnell, University of Toronto, Toronto, Ontario, Canada
  • Mathias Grote, Technische Universität Berlin, Germany
  • George A. Jacoby, Lahey Clinic, Burlington, MA
  • Mark Jones, Life Sciences Foundation, San Francisco, CA
  • Saleem Khan, University of Pittsburgh
  • Bruce Levin, Emory University, Atlanta, GA
  • John Mekalanos, Harvard Medical School
  • Marc van Montagu, Ghent University, Belgium
  • Richard Novick, New York University
  • David Sherratt, University of Oxford, UK
  • David Summers, University of Cambridge, UK
  • Chris Thomas, University of Birmingham, UK
  • Eva Top, University of Idaho, Moscow, ID
  • Gerhart Wagner, Uppsala University, Sweden
  • Michael Yarmolinsky, National Cancer Institute, Bethesda MD
  • Peter Young, University of York, UK

What are Plasmids?

Plasmids are small DNA molecules within cells that are physically separated from the chromosomal DNA. They are most commonly found in bacteria as small, circular, double-stranded, "naked" DNA molecules. The size of plasmids ranges from 1 to more than 1,000 kbp. Plasmids often carry genes that enhance the survival of the organism, such as genes for antibiotic resistance.

Plasmids are capable of replicating independently within a suitable host, but they do not encode genes necessary to encapsulate the genes for transfer to a new host. Thus, unlike viruses, plasmids are not generally considered to be a form of life.

In molecular cloning, artificial plasmids are used as vectors to drive the replication of recombinant DNA sequences within host organisms.

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