Technical guides and protocols for lateral flow assays.
Breaking the Cell Wall Detecting viruses or bacteria in plant leaves (e.g., TMV, Xylella) requires breaking robust cellulose walls. Standard buffers often fail. High-Salt & Detergent We recommend a lysis buffer containing PVP (Polyvinylpyrrolidone) to bind plant polyphenols, along with a non-ionic detergent. Due Bio’s “Ag-Grade” sample pads are pre-buffered to neutralize acidic plant saps … Read more
The 40nm Standard For most lateral flow assays, 40nm gold is the industry standard. It offers the best balance between color intensity (optical density) and steric stability against aggregation. When to Use 20nm? Smaller 20nm particles have a higher surface-area-to-volume ratio, allowing for higher antibody loading density. This can be advantageous for competitive assays where … Read more
The Optical Interface When moving from visual readouts to digital quantification, the membrane surface texture becomes critical. Rough membranes scatter light, creating “optical noise” for reflectance readers. Surface Smoothness Due Bio Universal Strips are cast with a controlled air-side surface roughness (Ra < 2μm). This minimizes background scatter, allowing handheld readers (like those from Axxin ... Read more
The “Stringy” Sample Saliva is patient-friendly but technically difficult due to mucins causing viscosity (stringiness). This halts flow on the strip. Mucolytic Sample Pads Our Universal Strips can be paired with our proprietary “Mucin-Busting” sample pad pretreatment, which breaks down glycoprotein networks instantly, allowing saliva to flow like water.
Why Fluorescence? Europium nanobeads offer 100x higher sensitivity than colloidal gold due to Time-Resolved Fluorescence (TRF) which eliminates background noise. Membrane Autofluorescence Standard nitrocellulose glows under UV light, killing your signal. Due Bio offers a special “Low-Fluorescence” grade membrane specifically cast for TRF readers.
False Negatives at Peak Infection In acute phases (e.g., COVID-19 or CRP spikes), excess antigen can saturate antibodies, causing the Test line to fade. This “Hook Effect” is dangerous. Three-Line Architecture We recommend adding a third “Hook Line” or using Due Bio’s high-capacity sample pads to sequester excess antigen, extending the linear range of your … Read more
Width Matters A strip cut at 3.8mm instead of 4.0mm contains 5% less reagent. This directly impacts line intensity and quantification. Rigid Backing Our Universal Strips utilize a high-rigidity PVC backing card that resists “blade drag” during high-speed guillotine cutting, ensuring every strip is mathematically identical.
The “Walking Pneumonia” Surge With the recent outbreaks of Mycoplasma pneumoniae in Asia and Europe, demand for rapid IgM/IgG detection is soaring. Sensitivity is key for pediatric samples. High-Flow Membranes Due Bio recommends using our HF135 Universal Strips. The balanced flow rate ensures sufficient antigen capture time for the relatively large Mycoplasma bacteria, boosting clinical … Read more
Traceability is Key For IVD manufacturers, every component must be traceable. Using generic, unbranded strips is a major non-conformance risk. Full Documentation Due Bio provides full CoA (Certificate of Analysis) and lot traceability for every pack of Universal Strips. Our manufacturing process aligns with ISO 13485 standards, simplifying your CE/FDA submission process.
Adhesive Failure Delamination usually occurs during the cutting process. If the backing card’s adhesive is too weak or too old, the membrane lifts off, disrupting capillary flow. The “Pressure” Factor Ensure your laminator applies consistent pressure (30-50 psi). Furthermore, Due Bio uses a high-tack acrylic adhesive backing that cures over time, providing a permanent bond … Read more