Rapid baculovirus titration assay based on viable cell side scatter (SSC)

Area of Science:

• Biotechnology
• Molecular Biology
• Virology

Background:

• Baculovirus expression systems are vital for recombinant protein production.
• Optimizing the multiplicity of infection (MOI) is key for efficient protein expression.
• Accurate virus titration is essential for determining the optimal MOI.

Purpose of the Study:

• To establish a novel, label-free, rapid, and simple method for baculovirus titration.
• To utilize viable cell side scatter (SSC) as a parameter for virus titration.
• To provide a more efficient alternative to standard titration methods.

Main Methods:

• Developed a label-free method for virus titration using viable cell side scatter (SSC).
• Measured SSC of cells infected with serial dilutions of baculovirus stock using flow cytometry at 48 h post-infection.
• Estimated infection probability and determined virus titer using a statistical method for wells with infection probabilities between 0.20 and 0.80.

Main Results:

• The SSC-based method demonstrated a strong correlation (R²=0.9853) with the standard plaque assay on a log scale.
• The proposed method is accurate and reliable for determining baculovirus titer.
• The method is simple, rapid, and label-free, facilitating efficient protein production.

Conclusions:

• The SSC-based flow cytometry method is a highly accurate and efficient tool for baculovirus titration.
• This method simplifies the process of optimizing MOI for recombinant protein production.
• The label-free nature and speed of this technique offer significant advantages for both laboratory and industrial applications.