Simple method for the concentration of influenza virus from allantoic fluid on microporous filters

Abstract

Membrane filter adsorption-elution is an efficient method for concentration and partial purification of several types of viruses from various aqueous solutions. For efficient virus adsorption to negatively charged filters, the sample is adjusted to pH 3.5 and trivalent salts are added before filtration. Since influenza virus is sensitive to extremes in pH, it cannot be concentrated by ordinary filters. Zeta Plus filters, which have a net positive charge of up to 5 or 6, were evaluated for the concentration of influenza virus from infectious allantoic fluids. Influenza virus efficiently adsorbed to Zeta Plus filters at pH 6, and addition of salts was not necessary. AdsoTbed virus was eluted in a small volume of 2% bovine serum albumin plus 1 M NaCl at pH 10. By this procedure, viruses in 100 ml of allantoic fluid were concentrated to a final volume of 8 ml, with an average recovery efficiency of 71.0%.

Simple method for concentration of bacteria from large volumes of tap water

“…The present study was undertaken to evaluate positively charged filters for concentration of bacteria by membrane adsorption-elution methodology. These filters consist of cellulose diatomaceous earth-"charge-modified"resin (series S, Zeta-plus; AMF CUNO, Meriden, Conn.) and have been reported to be useful for the concen-tration of human enteric viruses and bacteriophages at neutral or near-neutral pH values (6)(7)(8)14), thus eliminating the need for extensive acidification of the initial sample.…”

Rapid Detection of Salmonella spp. by Using Felix-O1 Bacteriophage and High-Performance Liquid Chromatography

“…The use of electropositive largepore filters has been shown to be very effective in removing Salmonella spp. and other microorganisms from water and sewage (5,7,8,11). Subsequent elution of these bacteria into nutrient broth would allow for the detection of Salmonella spp.…”

Critical Assessment of Purification and Analytical Technologies for Enveloped Viral Vector and Vaccine Processing and Their Current Limitations in Resolving Co-Expressed Extracellular Vesicles

“…A scalable process using a dual 0.45–0.2 µm filter has been proposed to clarify retroviral vectors produced in HEK293-derived cells [ 30 ]. NFF has also been used effectively for decades in the clarification process of influenza virus produced in embryonated chicken eggs [ 31 ].…”