Infection on a chip: a microscale platform for simple and sensitive cell-based virus assays

Area of Science:

• Virology
• Assay Development
• Drug Discovery

Background:

• The traditional plaque assay is the standard for measuring virus infectivity and screening antiviral drugs.
• However, the conventional plaque assay is labor-intensive, lacks sensitivity, and is difficult to automate.
• Recent advancements have focused on enhancing assay sensitivity through flow-enhanced virus spread and quantitative imaging.

Purpose of the Study:

• To develop and validate a microscale flow-enhanced infection assay for improved virus infectivity measurement.
• To assess the sensitivity and efficiency of this novel assay compared to the standard plaque counting method.
• To evaluate the potential of the assay for high-throughput drug screening and clinical diagnostics.

Main Methods:

• Microscale channels were utilized to perform flow-enhanced infection assays.
• Passive fluid pumping was employed for virus inoculation and to facilitate infection spread across cell monolayers.
• Quantitative imaging was used to measure infection, and results were compared to standard plaque counting.

Main Results:

• The flow-enhanced infection assay demonstrated a two-fold improvement in sensitivity compared to the standard plaque assay.
• The assay was tested using vesicular stomatitis virus infections in BHK cell monolayers with the antiviral drug 5-fluorouracil.
• The microscale format simplified fluid handling and enabled image-based quantification.

Conclusions:

• The developed microscale flow-enhanced infection assay offers significantly higher sensitivity and efficiency.
• This improved assay facilitates high-throughput drug screening, sero-conversion testing, and patient-specific viral diagnostics.
• The assay's reduced scale, simplified handling, and image-based quantification represent a substantial advancement over traditional methods.