Viraffinity™ - Virus and Viral Component Isolation

Since the COVID-19 virus can be detected in stool samples, it has been proposed that detection of the virus in wastewaters will help to monitor local or regional outbreaks. For this to succeed, simple and robust measurement of viruses from wastewater is necessary. Conventionally, enteric viruses are first concentrated by a variety of filter methods. A secondary enrichment step is often employed, to reduce to a final volume and improve purity prior to final analysis. This secondary step may be provided by the Viraffinity™ reagent, and does not require ultracentrifugation. As described in these two references: 1) Viraffinity™ can dramatically improve the purification of viruses, and 2) can remove RT-PCR inhibitors in the detection of enteric viruses.

1) Romain Fragnoud R., et al. "Differential proteomic analysis of virus enriched fractions obtained from plasma pools of patients with dengue fever or severe dengue". BMC Infectious Diseases (2015) 15:518. http://www.ncbi.nlm.nih.gov/pubmed/26572220

The article's authors report a method to compare the proteomes of virion-enriched fractions purified from plasma pools of patients with dengue fever or severe dengue. Virions were purified by ultracentrifugation combined with Viraffinity™. “…and became more intense after the Viraffinity™ step...Densitometry indicated that the protein complexity of the purified samples was reduced by roughly 350-fold compared to the unpurified samples.”.

2) Leggitt, Paris R., and Lee-ann Jaykus. "Detection methods for human enteric viruses in representative foods." Journal of Food Protection 63.12 (2000): 1738-1744.

“To optimize viral nucleic acid amplification, secondary PEG precipitates… required a prior adsorption step with an equal volume of Viraffinity™ to further remove RT-PCR inhibitors. In this case, viruses …were adsorbed by the addition of an equal volume of Viraffinity™, … These Viraffinity™ precipitates were used directly in subsequent RNA extractions.”

Viraffinity™

• Purifies whole infectious non-enveloped virus & non-infectious enveloped virus
• Complements ultracentrifugation, for viral proteomic enrichment 350X from plasma (Ref: Fragnoud et al, 2016)
• Isolates antigenic virions, enveloped and non-enveloped
• Enriches for viral nucleic acids
• Prepares viral samples for subsequent detection and analysis

Viraffinity™ is a unique water-insoluble elastomeric polyelectrolyte that has been engineered for the capture and recovery of viruses. Applications include: purification of whole infectious non-enveloped virus, virions, viral components, and sample preparation for subsequent detection and analysis. Viraffinity™ is directly added to the sample that is then mixed and centrifuged. The centrifuged pellet contains polyelectrolyte-bound viruses that can then be recovered using a moderately alkaline pH solution. Viraffinity™ is supplied as a suspension reagent ready for use. Simply pipette the suspension into the sample at the appropriate ratio, typically 1 volume of Viraffinity™; to 4 volumes sample. Viraffinity™ is also supplied as the enabling component of the ViraPrep™ application kits.

Viraffinity™ Product Sheet