Rethinking viral vector quantification: a microfluidic approach to standardised functional titre assays

Area of Science:

• Biotechnology
• Analytical Chemistry
• Cell and Gene Therapy

Background:

• Lentiviral vector (LVV) potency titration is crucial for cell and gene therapies.
• Conventional assays face limitations like inability to detect multiple integration events, procedural variations, and mass transport limitations.
• These issues cause inter-laboratory variability and underestimate true vector potency.

Purpose of the Study:

• To develop a microfluidic platform for precise lentiviral vector (LVV) potency quantification.
• To engineer a more reliable assay environment overcoming limitations of conventional methods.
• To establish a device-based analytical standard for cell therapy manufacturing quality testing.

Main Methods:

• Employed a microfluidic approach to create a precisely engineered assay environment.
• Systematically evaluated parameters including channel depth, incubation time, vector concentration, and multiplicity of infection (MOI).
• Assessed assay linearity, sensitivity, limit of detection, and reproducibility.

Main Results:

• A 0.2 mm deep microfluidic channel demonstrated comparable linearity and reproducibility to 96-well plates.
• The microfluidic assay offered shorter incubation periods and enhanced sensitivity.
• Detected LVV activity down to a MOI of 0.0625, a level undetectable by conventional well plates, corroborated by qPCR.

Conclusions:

• The microfluidic platform serves as a device-based analytical standard for functional titre quantification.
• Transforms a variable protocol into a reliable engineering solution for quality testing.
• Significantly improves reliability and accuracy in cell therapy manufacturing.