Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

DNA Bacteriophages

DNA Bacteriophages

Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to...

Osmotic Pressure

Osmotic Pressure

Osmosis is a process where solvent molecules move toward a solution through a semipermeable membrane. As the solution dilutes due to the entry of solvent, it expands. This expansion increases the hydrostatic pressure of the solution. When the hydrostatic pressure equals the osmotic pressure, osmosis stops.Osmotic pressure, denoted by Π, is the minimum pressure needed to prevent the solvent from passing into the solution by osmosis. The van 't Hoff equation calculates the osmotic pressure of an...

Viral Replication: Lysogenic Cycle

Viral Replication: Lysogenic Cycle

The lysogenic cycle is a crucial viral replication strategy that allows bacteriophages to persist within host cells without immediately destroying them. This process is primarily observed in temperate phages, such as bacteriophage lambda (λ), which infects Escherichia coli. The cycle allows the viral genome to persist across bacterial generations while keeping host cells viable.Integration of the Viral GenomeUpon infection, bacteriophage lambda attaches to the bacterial surface and injects its...

Viral Replication: Lytic Cycle

Viral Replication: Lytic Cycle

Bacteriophages, or phages, are viruses that specifically infect bacteria. Among them, T-even bacteriophages, such as T4, exhibit a well-characterized lytic replication cycle in Escherichia coli (E. coli). This process ensures the rapid proliferation of the virus while ultimately leading to the destruction of the bacterial host.Attachment and DNA InjectionThe infection process begins with the recognition and binding of the T4 phage to the E. coli cell surface. Tail fibers of the phage...

Osmosis and Osmotic Pressure of Solutions

Osmosis and Osmotic Pressure of Solutions

A number of natural and synthetic materials exhibit selective permeation, meaning that only molecules or ions of a certain size, shape, polarity, charge, and so forth, are capable of passing through (permeating) the material. Biological cell membranes provide elegant examples of selective permeation in nature, while dialysis tubing used to remove metabolic wastes from blood is a more simplistic technological example. Regardless of how they may be fabricated, these materials are generally...

Lytic Cycle of Bacteriophages

Lytic Cycle of Bacteriophages

Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the lytic replication...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

A Reconstituted Capsid-Nucleus Platform Uncovers Distinct Roles of UL25 and UL36 in Herpesvirus Capsid Docking.

Journal of molecular biology·2025

Same author

Navigating Muddy Waters and Protecting Yourself: Young People's Narratives of Men's Violence Against Women in Sweden.

Journal of interpersonal violence·2025

Same author

Soft jamming of viral particles in nanopores.

Nature communications·2024

Same author

Temperature-induced DNA density transition in phage λ capsid revealed with contrast-matching SANS.

Proceedings of the National Academy of Sciences of the United States of America·2023

Same author

'SAXS-osmometer' method provides measurement of DNA pressure in viral capsids and delivers an empirical equation of state.

Nucleic acids research·2023

Same author

Reconstituted virus-nucleus system reveals mechanics of herpesvirus genome uncoating.

QRB discovery·2023

Search research articles

Related Experiment Video

Updated: Jul 3, 2026

Following Cell-fate in E. coli After Infection by Phage Lambda

Following Cell-fate in E. coli After Infection by Phage Lambda

Published on: October 14, 2011

Osmotic pressure: resisting or promoting DNA ejection from phage?

Meerim Jeembaeva¹, Martin Castelnovo, Frida Larsson

¹Department of Biochemistry, Center for Molecular Protein Science, Lund University, Box 124, S-221 00 Lund, Sweden.

Journal of Molecular Biology

|July 8, 2008

Summary

Osmotic pressure enhances bacteriophage DNA ejection, contrary to previous findings. Crowded cellular environments and DNA-binding proteins further promote this process, aiding viral infection.

More Related Videos

Synthesis of Infectious Bacteriophages in an E. coli-based Cell-free Expression System

Synthesis of Infectious Bacteriophages in an E. coli-based Cell-free Expression System

Published on: August 17, 2017

Precise Phage Mutagenesis with NgTET-Assisted CRISPR-Cas Systems

Precise Phage Mutagenesis with NgTET-Assisted CRISPR-Cas Systems

Published on: October 14, 2025

Related Experiment Videos

Last Updated: Jul 3, 2026

Following Cell-fate in E. coli After Infection by Phage Lambda

Following Cell-fate in E. coli After Infection by Phage Lambda

Published on: October 14, 2011

Synthesis of Infectious Bacteriophages in an E. coli-based Cell-free Expression System

Synthesis of Infectious Bacteriophages in an E. coli-based Cell-free Expression System

Published on: August 17, 2017

Precise Phage Mutagenesis with NgTET-Assisted CRISPR-Cas Systems

Precise Phage Mutagenesis with NgTET-Assisted CRISPR-Cas Systems

Published on: October 14, 2025

Area of Science:

Molecular Biology
Biophysics
Virology

Background:

Previous in vitro studies suggested osmotic pressure hinders bacteriophage DNA ejection.
This hindrance was attributed to DNase I digestion of ejected DNA.
The role of osmotic pressure in undigested DNA ejection remained unclear.

Purpose of the Study:

To investigate the effect of osmotic pressure on intact bacteriophage DNA ejection.
To determine if cellular crowding and DNA-binding proteins influence ejection dynamics.
To explore the correlation between ejection efficiency and DNA packaging.

Main Methods:

Osmotic suppression experiments monitored by UV absorbance (without DNase I).
Pulse-field gel electrophoresis to analyze DNA integrity and ejection.
Cryo-transmission electron microscopy for visualizing ejection processes.
Simple scaling modeling to interpret experimental observations.

Main Results:

Intact genome ejection is enhanced by osmotic stress-induced DNA condensation, creating a pulling force.
Cellular crowding and DNA-binding proteins further increase the extent of DNA ejection.
Optimal crowding conditions for ejection correlate with previously observed optimal DNA packaging efficiencies.

Conclusions:

In vivo, the osmotically stressed cell cytoplasm likely promotes bacteriophage DNA ejection.
Crowding and DNA-binding proteins are key factors in facilitating viral genome delivery.
Findings provide insights into viral infection mechanisms and DNA packaging optimization.