Skip to main content

Detection of Bacteriophages: Statistical Aspects of Plaque Assay

  • 385 Accesses


Approaches to enumerating bacteriophages, as with microorganisms generally, tend to be limited by the small size of the subjects, which prevents unaided visualization of individuals. For phages, visualization is further hampered by our inability in most cases to view individual viruses even employing standard brightfield microscopy, which in any case would supply total rather than viable counts. A standard solution in microbiology towards obtaining viable counts involves plating, typically using Petri dishes to hold the plating medium and plated organisms. For cellular microorganisms we thus enumerate not individual viable cells but instead macroscopic clumps of cells as derived from the growth of individuals, that is, what we refer to as colonies. For phages, as well as viruses generally, such clumps not only cannot form on their own accord when employing solely abiotic growth media but also would tend to be invisible to the naked eye even given such concentrating. Instead, towards phage enumeration as well as viability determination, along with characterization of other properties, often what one counts are phage plaques. These too are areas of high organism concentration, though here as generated by localized phage replication rather than bacterial population growth. Plaques are not directly visible due to local phage presence, but instead as a consequence of a full or partial local absence of cells, that is, reduced cell numbers due to this localized phage propagation. Here we consider especially statistically derived best practices of plaque-based phage enumeration.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2


  • Abedon ST, Katsaounis TI (2018) Basic phage mathematics. Methods Mol Biol 1681:3–30

    CAS  CrossRef  Google Scholar 

  • Anderson B, Rashid MH, Carter C, Pasternack G, Rajanna C, Revazishvili T, Dean T, Senecal A, Sulakvelidze A (2011) Enumeration of bacteriophage particles: comparative analysis of the traditional plaque assay and real-time QPCR- and nanosight-based assays. Bacteriophage 1:86–93

    CrossRef  Google Scholar 

  • Carlson K (2005) Working with bacteriophages: common techniques and methodological approaches. In: Kutter E, Sulakvelidze A (eds) Bacteriophages: biology and application. CRC Press, Boca Raton, pp 437–494

    Google Scholar 

  • Carlson K, Miller ES (1994) Enumerating phage: the plaque assay. In: Karam JD (ed) Molecular biology of bacteriophage T4. ASM Press, Washington, DC, pp 427–429

    Google Scholar 

  • DeGroot MH (1975) Probability and statistics. Addison-Wesley, Boston

    Google Scholar 

  • Hyman P, Abedon ST (2009) Practical methods for determining phage growth parameters. Methods Mol Biol 501:175–202

    CAS  CrossRef  Google Scholar 

  • Kropinski AM, Mazzocco A, Waddell TE, Lingohr E, Johnson RP (2009) Enumeration of bacteriophages by double agar overlay plaque assay. Methods Mol Biol 501:69–76

    CAS  CrossRef  Google Scholar 

  • Kutter E (2009) Phage host range and efficiency of plating. Methods Mol Biol 501:141–149

    CAS  CrossRef  Google Scholar 

  • Letarov AV, Kulikov EE (2018) Determination of the bacteriophage host range: culture-based approach. Methods Mol Biol 1693:75–84

    CAS  CrossRef  Google Scholar 

  • Mazzocco A, Waddell TE, Lingohr E, Johnson RP (2009a) Enumeration of bacteriophages by the direct plating plaque assay. Methods Mol Biol 501:77–80

    CAS  CrossRef  Google Scholar 

  • Mazzocco A, Waddell TE, Lingohr E, Johnson RP (2009b) Enumeration of bacteriophages using the small drop plaque assay system. Methods Mol Biol 501:81–85

    CAS  CrossRef  Google Scholar 

  • Moore DS, Notz WI (2014) Statistics, concepts and controversies. W.H. Freeman Co., New York

    Google Scholar 

Download references

Author information

Authors and Affiliations


Corresponding author

Correspondence to Stephen T. Abedon .

Editor information

Editors and Affiliations

Rights and permissions

Reprints and Permissions

Copyright information

© 2019 Springer Nature Switzerland AG

About this entry

Verify currency and authenticity via CrossMark

Cite this entry

Abedon, S.T., Katsaounis, T.I. (2019). Detection of Bacteriophages: Statistical Aspects of Plaque Assay. In: Harper, D., Abedon, S., Burrowes, B., McConville, M. (eds) Bacteriophages. Springer, Cham.

Download citation

  • DOI:

  • Received:

  • Accepted:

  • Published:

  • Publisher Name: Springer, Cham

  • Print ISBN: 978-3-319-40598-8

  • Online ISBN: 978-3-319-40598-8

  • eBook Packages: Springer Reference Biomedicine & Life SciencesReference Module Biomedical and Life Sciences