If you’re a researcher working on COVID-19 related workflows, from enabling detection of the virus to development of a vaccine, we’d like to help — with filtration products that ensure reliable and consistent results. Our Scientific and Laboratory Services (SLS) team can offer guidance based on individual application needs to match the best filtrations solutions for each application.

For reference, here are some applications and products being used by researchers.

Sterile filtration of media, kits, and reagents for COVID-19 research

Researchers are using AcroPak™ capsules and Acrodisc™ sterile syringe filters (Pall™ Life Sciences products) to ensure the sterility of media, kits, and components used in research kits for COVID-19. These products provide peace of mind for accuracy and reliability of sterile filtration, so developers can be confident in the products they manufacture.

AcroPak™ capsules come in various sizes and can filter up to 150 L. They include bacterial reduction and quality claims and are 100% integrity-tested for extra assurance of performance and quality. We offer Scale-Up capsules that feature the same performance and materials as our GMP Pharmaceutical grade capsules and filters, which can help streamline and quicken scale-up or scale out operations.

Acrodisc™ sterile syringe filters are well-suited for small-volume aseptic handling and sterile filtration of up to 150 mL solutions. They’re available in multiple membrane sizes and types for nearly all applications.

Viral concentration of COVID-19

Researchers are using the Minimate™ Tangential Flow Filtration (TFF) system (Pall™ Life Sciences products) to achieve high concentrations of viral proteins in a faster, more efficient process compared to centrifugal devices or stirred cells. The Minimate™ system can easily concentrate viral proteins from solutions of up to 1 L.

The Minimate™ TFF system is well-suited for lab-scale tangential flow applications for volumes up to 1 L and can efficiently concentrate, buffer exchange, or diafilter. Our Minimate™ EVO system features reusable capsules with Omega™ ultrafiltration membranes that are well-suited to concentrate proteins, nucleic acids, viral particles, and nanoparticles. For smaller starting volumes of less than 50 mL, we offer centrifugal devices that use the same Omega™ membrane.

QC testing of drug candidates for COVID-19 research

Acrodisc™ Syringe Filters (Pall™ Life Sciences products) are being used to clean up samples prior to HPLC and other methods of downstream analysis where a particulate-free sample is vital. Designed for optimal filtration and featuring a universally solvent-compatible wwPTFE membrane, Acrodisc™ Syringe filters are available in multiple sizes and diameters to minimize sample loss and maximize throughput.

For small volumes, we offer the 13 mm Acrodisc™ syringe filter with a minispike outlet. Benefits of the minispike include:

  • 50% reduced hold-up volume of the sample, making it comparable to a 4 mm syringe filter
  • Small diameter of the outlet allows for the minispike outlet to filter directly into HPLC vials, without creating a seal that could cause an airlock and halt filtration

For larger volume samples up to 125 mL, the 25 mm Acrodisc™ syringe filter is the preferred choice and is available with a pre-filter for difficult or dirty samples. Benefits include:

  • Available in 0.2 μm and 0.45 μm pore sizes for UHPLC and HPLC applications
  • Polypropylene housing enables chemical resistance and low sample binding
  • Clean filtrate for highly sensitive applications

Extraction of RNA from COVID-19 virus

Both the Nucleic Acid Binding (NAB) Nanosep™ spin device and AcroPrep™ filter plates (Pall™ Life Sciences products) are being used for RNA extraction of COVID-19 prior to RT-PCR.

The NAB Nanosep™ centrifugal device is well-suited for research applications. It provides high yields that can generate enough sample for multiple downstream applications, thus saving time and money by eliminating the need to process additional samples. The high quality of the resulting RNA is the key to success in many downstream applications and makes these spin devices ideal for labs with low to medium throughput.

The AcroPrep filter plate with glass fiber membrane is well-suited for isolating nucleic acids in high throughput and within semi or fully automated laboratories. They are truly high-throughput in 9-6 and 384-well plate formats that are automation compatible. AcroPrep filter plates can extract high yields of viral RNA making them an excellent solution for high-throughput isolation prior to RT-PCR.

The NAB Nanosep™ centrifugal device is a plug-and-play solution for RNA, gDNA, and pDNA extraction, which allows researchers to utilize leftover reagents that have collected in their labs. The NAB Nanosep device can be used with a variety of starting materials such as mammalian cells, plant tissue, and bacteria. Numerous protocols are available online, along with a Quick Start Guide to illustrate how easily this device can be integrated into a researcher’s exiting workflow.

Testing performance of N95 respirators

The global shortage of N95 masks has led to the purchase of substitutes, which raises the question of how effective these respirators are in protecting against the viral or particle transmission. Our A/E glass fiber filters are being used to test the performance and quality of N95 respirators and equivalents to demonstrate how well the masks block virus particles. These membrane disc filters can also be used for testing dissolved and suspended solids in wastewater and gravimetric analysis of air pollutants.

The A/E membrane with a 1.0 µm glass fiber filter is an excellent choice where gross filtration is required, to remove impurities before processing downstream. This membrane disc is available in 25 mm and 37 mm diameters.

Wastewater surveillance for COVID-19

Research is ongoing to test wastewater for COVID-19 as a means to detect potential outbreaks of infection in a population or region before it is identified through patient testing. Our Jumbosep™ centrifugal devices are being used to concentrate COVID-19 virus in wastewater to help predict outbreaks and adopt protective measures. Initial collection volumes are ~ 120 mL, and the samples are first concentrated in the Jumbosep™ centrifugal device and then moved to a Microsep™ centrifugal device to concentrate further down to 200 µL.

Our centrifugal devices simplify many common nucleic acid and protein sample preparation steps.

They accelerate sample processing, maximize sample recovery, add versatility, prevent solution bypass, and feature the high-performance Omega™ membrane for fast, efficient filtration. We have a complete lineup of centrifugal devices (Pall™ Life Sciences products):

  • Nanosep™ centrifugal device: 50 µl to 500 µL
  • Microsep™ centrifugal device: 0.5 mL to 5 mL
  • Macrosep™ centrifugal device: < 20 mL
  • Jumbosep™ centrifugal device: 20 mL to 60 mL

Conjugated viral particles

The Centramate™ SS tangential flow system (TFF) (Pall™ Life Sciences products) is being used to concentrate up to 10 L of conjugate to help develop a rapid COVID-19 test. The Centramate™ systems proven bioprocess components offer high reliability and a compact flow path with the ability to scale from 1 to 125 L.

The Centramate™ SS is a stainless-steel holder, and the Centramate cassettes feature Omega™ membranes for ultrafiltration of proteins, viruses, and nanoparticles or Supor membranes for microfiltration applications. The Centramate™ holder is also available in a PE (polyethylene) version and a LV (low volume) version.

Viral collection of COVID-19 in air

While people around the world are spending time indoors, we need to know whether COVID-19 is present in the air of indoor environments. Research has been published using PTFE membrane discs and open-faced filter holders to collect COVID-19 in air samples (1).

We offer a wide variety of PTFE membrane discs both supported and unsupported, and in a variety of pore sizes. We also provide open face filter holders in stainless steel, aluminum and in two- and three-piece cassettes

Learn about our lab filtration solutions.

References

  1. Rahmani AR, Leili M, Azarian G, Poormohammadi A. Sampling and detection of corona viruses in air: A mini review. Sci Total Environ. 2020;740:140207. doi: 10.1016/j.scitotenv.2020.140207.