Membrane consistency for assay reproducibility and sensitivity
- Increased sensitivity
Vivid Lateral Flow Nitrocellulose (LFNC) membranes provide high sensitivity with dilute concentrations of target analytes.
- Strong consistency and high duplication rate
When measuring intra- and inter-lot performance for wicking time and thickness Vivid LFNC membranes provide consistent results, resulting in low defined coefficients of variation.
- Consistent reproducibility
Provides protein binding levels which are highly consistent to facilitate reliable assay performance.
- Clear results
Demonstrates low background levels which enable crisp capture lines and easy-to-read results.
- Dependable performance
Constructed using pure nitrocellulose that does not contain interfering substances or post-treatments that affect assay performance.
- Clear surface appearance
Controlled surface quality of the membrane ensures freedom from visual defects, discolouration and dust.
- Result timing
Quality assured wicking speed gives predictable result time.
Nitrocellulose membranes are the heart of lateral flow assays and require highly consistent wicking rate and thickness. Variations in either can have detrimental effects on assay sensitivity, reproducibility, and reagent consumption.
Vivid LFNC membranes are manufactured to ensure that these key parameters are tightly controlled with coefficients of variation (CV) between 5 and 10%.
Nitrocellulose is the globally preferred membrane substrate in diagnostic tests where antigenantibody binding occurs, e.g., pregnancy tests, urine-albumin tests and C-reactive protein (CRP) detection. Pall’s Vivid LFNC membranes fulfil all the criteria to enable the development and manufacture of a diverse range of tests with reliability and reproducibility, available with the following benefits:
- Quality: designed and tested specifically for diagnosticapplications to ensure the materials meet stringent requirements for diagnostic assay development and manufacturing
- Reliable, large-scale manufacturing capacity with lot to lot traceability
- Reproducibility: defined coefficients of variation for key performance parameters result in consistent performance
- Choice of defined capillary speeds to select sensitivity of diagnostic test
- Straight and uniform migration front
|Membrane||Thickness||Wicking Rate (s / 4 cm)|
|190 – 230 μm includes 95 – 105 μm polyester support||70 - 110|
|190 - 230 μm includes 95 – 105 μm polyester support||95 - 135|
The thickness of the reaction membrane has a direct impact on its signal generation. Consequently, any variations both intra- or inter-lot will have an impact on Point of Care Test (POCT) device manufacturing and the final assay performance.
In the data drawn from 3 lots, measuring the thickness of the membrane every 2.5 cm down a sample piece of material, the coefficient of variation was measured as ≤4.6% for Vivid 120 LFNC membrane with average thickness for all sample points being 196.7 ± 8.1 μm (Graph 1) and for Vivid 90 LFNC membrane the coefficient of variation was ≤2.6% with average thickness for all sample points being 217.1 ±
Assay sensitivity is maintained with consistency of the wicking rate of the nitrocellulose membrane. By maintaining a uniform sample front that travels along the membrane at a consistent speed, the target analyte is maintained in a homogenous concentration. This ensures that the target analyte present in the sample has adequate time to bind to the capture antibody resulting in reproducible results from lot to lot. The wicking rate of the Vivid 90 and Vivid 120 LFNC membranes both exhibit CV’s for intra- and inter-lot consistency of ≤ 10% (Table 2 and 3).
|Membrane||Inter-lot Wicking Rate (s / 4 cm)||Average (s / 4 cm)||Standard Deviation||Coefficient of Variation|
|Lot 1||Lot 2||Lot 3|
|Vivid 90 LFNC||83.7||79.3||87.3||83.4||6.1||7.3%|
|Vivid 120 LFNC||130.7||117.3||117.7||121.9||7.8||6.4%|
Table 2: Summary data of intrer-lot reproducibility (from three sample points) of capillary speed and inter-lot reproducibility across three lots.
|Membrane||Intra-lot Wicking Rate (s / 4 cm) Position on Sample Sheet||Average (s / 4 cm)||Standard Deviation||Coefficient of Variation|
|Vivid 90 LFNC||80.7||84.3||85.3||83.4||2.5||2.9%|
|Vivid 120 LFNC||117.7||123.0||125.0||121.9||3.8||3.1%|
Table 3: Summary data of intra-lot reproducibility (from three sample points) of capillary speed and inter-lot reproducibility across three lots.
Scanning Electron Microscopy
Removal of white blood cells to prevent interference with PCR or molecular diagnostics.
Removal of cellular components (red cells, white cell, platelets) in less than two minutes resulting in a supernatant with similar qualities to centrifuged material.
Pall Corporation and Diagnostics
Pall Corporation is a global leader in high-tech filtration, separation, and purification, serving the diverse needs of customers across the broad spectrum of life sciences and industry. Pall works with customers to advance health, safety and environmentally responsible technologies. The Company’s engineered products enable process and product innovation and minimize emissions and waste.
Our extensive portfolio of membrane and media products serve applications from diagnostics to venting, worker and equipment protection as well as Intravenous drug delivery.
Medical diagnostic teams need a reliable business partner with expertise in technology innovations and state of the art engineering. Pall executes manufacturing to ensure regulatory compliance and meet quality standards. Our diagnostic products are manufactured in accordance with ISO 9001.
Pall understands that the world of medical diagnostics gets more complicated every day. We know that you’re counting on our team to provide you with quality products, so that you can provide your patients with insight and resolution.
|Description||Wicking Rate (s / 4 cm)||Width||Length||Pkg||Part Number|
|Vivid 120 LFNC Sample||95 - 135||25 mm||300 mm||1 Strip||VIV120SAMP|
|Vivid 120 LFNC||95 - 135||25 mm||3 metres||1 Roll||VIV1202503R|
|Vivid 120 LFNC||95 - 135||25 mm||50 metres||1 Roll||VIV1202550R|
|Vivid 90 LFNC Sample||70 - 110||25 mm||300 mm||1 Strip||VIV90SAMP|
|Vivid 90 LFNC||70 - 110||25 mm||3 metres||1 Roll||VIV902503R|
|Vivid 90 LFNC||70 - 110||25 mm||50 metres||1 Roll||VIV902550R|