Journal: Frontiers in Bioengineering and Biotechnology

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

doi: 10.3389/fbioe.2026.1720882

Figure Lengend Snippet: Design and physical characterization of the microchannel device. (A) Photographic image of two microfluidic devices. Each device features one inlet and one outlet connector to a cell culture chamber (filled with methylene blue dye for better visualisation). The microchannel structures were made from polydimethylsiloxane (PDMS) and bonded to a cyclo-olefin copolymer (COC) microscope slide. Scale bar = 10 mm. (B) Top view drawing of the microchannel device with corresponding key dimensions represented in millimetres. The area of the culture chamber is approximately 0.39 cm 2 , similar to the surface area of a single well of a 96-well plate (0.32 cm 2 ). (C) Characterisation of microchannel depth by optical profilometry. The micro-machined height of the polycarbonate (PC) mould and the corresponding depths of the PDMS channels were compared to verify the accuracy of the PDMS casting. The channel depths expected by the design are indicated by the dashed lines. All data points are presented as mean ±1 standard deviation of technical triplicates. Significance was assessed using un-paired T-test (p > 0.05).

Article Snippet: Microchannel moulds were designed in Fusion v2.0.20981 (Autodesk, United States), manufactured using CNC milling from 3 mm thick polycarbonate (PC) sheets.

Techniques: Cell Culture, Microscopy, Standard Deviation

Journal: Frontiers in Bioengineering and Biotechnology

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

doi: 10.3389/fbioe.2026.1720882

Figure Lengend Snippet: Comparison of transduction efficiency (TE) obtained by maintaining constant either the (A) MOI of 2 or the (B) LVV concentration (TU mL -1 ) of 6.3 × 10 5 TU mL -1 . This was evaluated across 3 microchannels with different culture fluid overlay with a 24h incubation between the LVV particles and target cells. (C) TE evaluated across a range of MOI values: 0.5, 1, 2 and 4. All experiments were performed in parallel in a 96-well plate and a set of microchannels representing various channel depths. (D) Transduction efficiency comparing a 96-well plate well with an ∼1.5 mm culture overlay and a 1.5 mm microchannel. Data points are presented as mean ±1 standard deviation (n = 2, 3). Significance was assessed using one-way ANOVA with Dunnett’s post hoc analysis (ns: p > 0.05; *: p < 0.05; **: p < 0.01; ***: p < 0.001; ****: p < 0.0001).

Article Snippet: Microchannel moulds were designed in Fusion v2.0.20981 (Autodesk, United States), manufactured using CNC milling from 3 mm thick polycarbonate (PC) sheets.

Techniques: Comparison, Transduction, Concentration Assay, Incubation, Standard Deviation

Journal: Frontiers in Bioengineering and Biotechnology

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

doi: 10.3389/fbioe.2026.1720882

Figure Lengend Snippet: Assessment of linearity, reproducibility and incubation time of the microchannel assays. (A) Linearity evaluated using 4 MOI values, using the following channel depth: 1.5 mm (plate) and 1, 0.6 and 0.2 mm (microchannels). (1.5 mm: R 2 = 0.9593; 1.0 mm: R 2 = 0.8721; 0.6 mm: R 2 = 0.9270; 0.2 mm: R 2 = 0.9798). (B) Assay reproducibility evaluated across three experimental occasions for each channel depth (mm). Each experiment was performed in technical triplicates, i. e., for every channel depth three devices were evaluated in parallel. (CV: 1.0 mm: 11%; 0.6 mm: 3.4%; 0.2 mm: 3.9%). (C) Heatmap outlining the extent of transduction efficiency obtained across several incubation times between the LVV material and target cells. This is performed at a constant MOI of 1. All data is representative of the mean from triplicate measurements ±1 standard deviation. Significance was assessed using one-way ANOVA with Dunnett’s post hoc analysis (ns: p > 0.05; *: p < 0.05; **: p < 0.01; ***: p < 0.001; ****: p < 0.0001).

Article Snippet: Microchannel moulds were designed in Fusion v2.0.20981 (Autodesk, United States), manufactured using CNC milling from 3 mm thick polycarbonate (PC) sheets.

Techniques: Incubation, Transduction, Standard Deviation

Journal: Frontiers in Bioengineering and Biotechnology

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

doi: 10.3389/fbioe.2026.1720882

Figure Lengend Snippet: Identifying the impact of microchannel transductions on assay sensitivity compared with 96-well plates. (A) Quantification of vector genome copies per cell, measured by qPCR. (B) The fraction of GFP-positive cells determined by flow cytometry. All values are presented as mean of n = 3 with error bars indicating ±1 standard deviation of the mean. Significance was assessed using one-way ANOVA with Dunnett’s post hoc analysis (ns: p > 0.05; *: p < 0.05; **: p < 0.01; ***: p < 0.001; ****: p < 0.0001).

Article Snippet: Microchannel moulds were designed in Fusion v2.0.20981 (Autodesk, United States), manufactured using CNC milling from 3 mm thick polycarbonate (PC) sheets.

Techniques: Plasmid Preparation, Flow Cytometry, Standard Deviation