Real-Time
complex Size
monitoring for Transfection

Current Challenges in Transfection Complex Size monitoring

Transient transfection performance is sensitive to transfection complex size. When the optimal size window is narrow, small shifts during mixing can lead to variability, repeat work, and yield loss.

The therapeutic efficacy, stability, and safety of these products depend heavily on the formation of particles within precise size ranges.

Most pharmaceutical manufacturers are forced to time the nanoparticle formation processes.

 They rely on:

• Guesswork during scale-up
• Fixed mixing durations
• Offline sampling and analysis

Top 5 challenges

1. Sampling can compromise sterility and adds contamination risk
2. Measurements are often destructive (you lose material and disturb the system)
3. Lack of real-time insight during complex formation
4. Slow feedback loops and extra handling add variability
5. Hard to standardize and transfer complexation protocols

The NanoLabSizer, launched in 2026, enables real-time, non-invasive nanoparticle size analysis using Spatially Resolved Dynamic Light Scattering (SR-DLS).

• No need to stop your process
• No sample extraction
• No compromise on sterility

Measure directly through any transparent container, including:

• IV bags
• Glass or plastic vials
• Prefilled syringes
• Bioreactor bags

Understanding

Helps to accelerate development, scale-up and validation

• Direct link between complex size and batch yield
• Continuous, data-rich size–growth curves instead of current offline approach
• More representative size data by avoiding sampling and measurement delays

Efficiency

Shorter time, less experiments, less manhours

• Eliminates destructive sampling and “sacrifice” transfection batches
• Continuous kinetics reduces the number of experiments
• No skilled lab personnel or sample handling needed

Direct savings

Costs of materials, waste, number of batches, labour

• No extra non-sterile batch for offline size analysis
• 15–30% higher titre/yield from more accurate, scalable recipes
• No sampling disposables or hands-on time thanks to continuous readout

The NanoLabSizer Measures

• Complex size and growth
• Data collection every 5-10 seconds
• Aggregation
• Stabilization points

Optimizing the size of pDNA–PEI complexes is critical because both overly small and overly large particles undermine transfection performance.

• How can you measure particle size CQAS in (sterile) packaging?
• Whitepaper – How do results from different DLS instruments compare?
• Whitepaper – Inline detection of aggregates and oversized particles