Technical guides and protocols for lateral flow assays.
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
The Tropical Challenge Dengue and Malaria assays must function in high-temperature, high-humidity environments. Standard membranes often degrade or slow down under these conditions. Tropical-Ready Membranes Due Bio’s “Tropical-Grade” Universal Strips are manufactured with a stabilized pore structure that resists humidity-induced aging, ensuring reliable flow even in field clinics across SE Asia and Africa.
Capture vs. Detection In a sandwich assay, the Capture Antibody (on the T-line) and Detection Antibody (on the Gold) must bind to different epitopes. Steric hindrance is a common failure mode. Screening Protocol We recommend a “Checkerboard” screening approach using Due Bio Universal Strips. Test Antibody A (Capture) against Antibody B (Detection), and then swap … Read more
More Than Just Saline A running buffer isn’t just a vehicle; it’s a chemical tool. To boost sensitivity in Due Bio Universal Strips, we recommend tuning your buffer with: Surfactants (0.5-2%): Tween-20 or Triton X-100 to reduce hydrophobic interactions. Blocking Proteins (1% BSA): To coat the membrane surface and prevent background. Viscosity Modifiers (PVP/PEG): To … Read more
No C-Line = No Result A missing Control (C) line renders the test invalid. Common causes include: Conjugate Death: Gold nanoparticles aggregated or antibodies denatured. Membrane Dry-out: Old strips stored without desiccants. Flow Obstruction: Sample pad clogging preventing liquid from reaching the C-line. Switching to Due Bio robustly packaged and stabilized strips can reduce invalid … Read more
More Than Just Plastic The backing card provides rigidity, but its adhesive layer is the unsung hero. Weak adhesive leads to “delamination” during cutting, while overly aggressive adhesive can migrate into the membrane and block pores. Medical-Grade PSA Due Bio Universal Strips use a medical-grade Pressure Sensitive Adhesive (PSA) that is chemically inert and solvent-free, … Read more
The Nightmare of Lot Variation You validated your assay on Lot A, but Lot B gives false positives. Sound familiar? Variation in nitrocellulose casting thickness is the #1 killer of LFA projects. Our QC Standard Due Bio uses automated reel-to-reel laser inspection to monitor membrane thickness to within ±1 micron. We guarantee Inter-Lot CV < ... Read more
Competitive vs. Sandwich Unlike COVID-19 (sandwich assay), detecting small molecules like Glyphosate or Antibiotics requires a Competitive Assay format. Here, the T-line intensity decreases as analyte concentration increases. Critical Tuning Competitive assays are highly sensitive to membrane flow rate. A slower wicking speed (e.g., 180s/4cm) is crucial to allow sufficient competition at the test line. … Read more
The ASFV Challenge African Swine Fever Virus (ASFV) requires early detection to prevent herd devastation. Standard colloidal gold strips often miss low viral loads in the incubation phase. Enhancing Sensitivity To detect ASFV at pogram levels, we recommend using Due Bio High-Bind Nitrocellulose combined with Europium bead labels (fluorescent LFA). Our membranes are optimized for … Read more
Flow Rate vs. Surface Area Smaller pores (e.g., 8μm) offer higher surface area for antibody binding and slower flow, increasing sensitivity. Larger pores (12-15μm) allow faster flow but reduce reaction time. Selection Strategy For high-sensitivity CRISPR assays, we typically recommend 10μm or 12μm membranes as the optimal balance. Due Bio provides a range of defined … Read more