Related Experiment Video
Updated: Aug 17, 2026
Aseptic Laboratory Techniques: Plating Methods
Published on: May 11, 2012
Plaque assay of baculoviruses employing an agarose-nutrient overlay
Abstract:
Four baculoviruses produced visible plaques in the Spodoptera frugiperda cell line when cell monolayers were infected and overlayed with a simplified, agarose-nutrient formulation. Macroscopic plaques were first detected 4 days postinoculation, and by 10 days plaques ranging from 0.5 to 3 mm in diameter were seen. Dose-response experiments indicated that a single particle initiated the formation of a plaque, because a linear response was demonstrated with increased dosage.
Insights
Researchers developed a simplified agarose-nutrient method to visualize baculovirus plaques in Spodoptera frugiperda cells. This technique allows for the detection of single viral particles initiating plaque formation, crucial for viral quantification and study.
Area of Science:
- Virology
- Cell Biology
- Molecular Biology
Background:
- Baculoviruses are important tools in molecular biology and biotechnology.
- Efficient methods for quantifying baculovirus infectivity are essential for research and application.
- Previous plaque assay methods could be complex or time-consuming.
Purpose of the Study:
- To develop and validate a simplified agarose-based plaque assay for baculoviruses.
- To determine the minimum infectious unit required for plaque formation.
- To establish a reliable method for visualizing and quantifying baculovirus plaques.
Main Methods:
- Infection of Spodoptera frugiperda cell monolayers with four different baculoviruses.
- Overlaying infected cell monolayers with a simplified agarose-nutrient formulation.
- Macroscopic observation and measurement of viral plaques over time (4-10 days postinoculation).
- Conducting dose-response experiments to correlate viral dosage with plaque formation.
Main Results:
- Visible macroscopic plaques were consistently produced by four tested baculoviruses.
- Plaques were first detected at 4 days postinoculation and reached 0.5–3 mm diameter by 10 days.
- Dose-response experiments demonstrated a linear relationship between viral dosage and plaque formation.
- The results indicate that a single viral particle initiates the formation of a single plaque.
Conclusions:
- A simplified agarose-nutrient formulation enables efficient plaque formation and visualization of baculoviruses.
- This assay is sensitive enough to detect plaque formation initiated by single viral particles.
- The developed method provides a reliable and accessible tool for baculovirus quantification and infectivity studies.
