In this interview, News-Medical talks to Hasret Altan-Martin from Sartorius about the ongoing emergence of lateral flow assays in diagnostics.
How has the COVID-19 crisis changed our thinking about LFAs?
Before the COVID-19 pandemic, the pregnancy test was the most prominent rapid test on the market besides other tests to detect infectious diseases, such as HIV, flu, and malaria. The SARS-COV-2 virus has changed that tremendously. The virus spread fast, with a severe impact on human health, making it necessary to produce a reliable and cheap tool to detect the virus at home. This was so important to minimize the danger of further infections.
The tool of choice was a well-established and well-known lateral flow assay (LFA) method. Big manufacturers had existing platforms that they could use and adjust to the occurring needs. That was why the first Over-the-Counter Covid-19 rapid antigen tests were available in Autumn 2020. Since then, LFAs are omnipresent and awareness of them has increased worldwide.
What makes LFAs so successful?
LFAs have many advantages. First, LFAs quickly provide reliable results, which can be qualitative, semi-quantitative or quantitative. They are cheap compared to laboratory diagnostics and readily available in drug stores and pharmacies. Their ease of use makes them convenient for every end-user since no special training is needed. In addition, LFAs can be used everywhere, independent of laboratory infrastructure. These properties make rapid tests so successful.
What makes the perfect LFA?
A LFA consists of different components. Each is important and contributes to a reliable and robust test result. Understanding the interactions and finding the right balance is the key to a perfect LFA.
The motor of each LFA is the nitrocellulose membrane. It is the matrix where all reagents flow along the strip driven by capillary forces. The membrane itself has a sponge-like porous structure. Depending on the membrane's pore sizes and the fluid's viscosity, the reactants flow with different velocities along the membrane and reach the test line. Here, the naked eye or a reader can detect the actual reaction. This makes the nitrocellulose membrane so crucial for the functionality of a LFA.
Why should you choose the Unisart® CN membranes?
Membrane manufacturing is one of Sartorius’ core technologies. Being the first industrial manufacturer of nitrocellulose membranes in 1927, Sartorius combines in-depth know-how with application expertise. The Unisart® CN membrane portfolio results from our extensive experience and constantly strive to serve the diagnostic market's needs best.
One of the primary qualities of our Unisart® CN membranes is the exceptional inter- and intra-lot consistency. Consistent membrane performance and the membranes' homogenous structure and smooth surface guarantee reliable and reproducible test results.
Our customers can rely on a highly motivated and experienced service, sales, and application specialist team ready to support them in the best way. We offer an excellent package for our customers to simplify and accelerate progress.
What makes Unisart® CN 180 DX so special and for which kind of tests is it suitable?
Unisart® CN 180 DX is the newest member in the Unisart® CN membrane portfolio, resulting from intensive work and research. It combines high protein binding capacity with superior sensitivity for critical applications, such as infectious diseases (e.g. HIV and malaria).
Due to the increased inner surface area of the membrane, more protein can be bound. The combination of increased protein binding and decreased capillary speed gives enhanced signal intensity. This makes Unisart® CN 180 DX the membrane of choice for critical applications where sensitivity is crucial.
What is the next generation of Unisart® CN membranes?
Sartorius has developed a new technology platform enabling multiplexing and leading to a multiparameter lateral flow strip: the Unisart StructSure® membrane. The innovative process allows the engraving of nitrocellulose membranes. Hydrophobic barriers separate the remaining nitrocellulose membrane channels from each other, preventing any overflow of liquid. Different patterns with various lanes can be created, leading to multiple reaction zones.
The advantage of Unisart StructSure® is the possibility to miniaturize the test and detect different targets from a single source simultaneously. This also reduces sample volume, e.g. liquor and tear fluid, compared to a single assay type.
Every membrane type of our Unisart® CN membrane portfolio can be used for multiplexing, giving us a high degree of flexibility to provide our customers with the most advanced and innovative solution.
Solutions for Lateral Flow Assays & In Vitro Diagnostics Kit (IVD) Manufacturers
The diagnostic industry plays an essential role in healthcare, not only by providing essential tools to clinicians, but also by supplying a range of at-home testing solutions. Sartorius is globally recognized for an expertise in biotherapeutics, including solutions for in vitro diagnostics kit (IVD) manufacturers. Discover more
Where can readers find more information?
About the Researcher
Hasret studied biochemistry at Goethe University in Frankfurt. After her Ph.D. in Molecular Cell Biology, she joined Fassisi and worked on the optimization of lateral flow assays for veterinary rapid diagnostics. In 2017, she started as a scientist at Sartorius, a leading international partner for the biopharma sector, where she helped to develop membranes for venting applications. Since 2021, Hasret is responsible for the Unisart® CN Membrane portfolio as a product manager.
About Sartorius Lab Instruments GmbH & Co. KG
The Sartorius Group is a leading international partner of life science research and the biopharmaceutical industry.
With innovative laboratory instruments and consumables, the Group’s Lab Products & Services Division concentrates on serving the needs of laboratories performing research and quality control at pharma and biopharma companies and those of academic research institutes.
The Bioprocess Solutions Division with its broad product portfolio focusing on single-use solutions helps customers to manufacture biotech medications and vaccines safely and efficiently. The Group has been annually growing by double digits on average and has been regularly expanding its portfolio by acquisitions of complementary technologies.
In fiscal 2021, the company earned sales revenue of some 3.45 billion euros. At the end of 2021, nearly 14,000 people were employed at the Group’s approximately 60 manufacturing and sales sites, serving customers around the globe.