title: Phage passage after extended processing in small-virus-retentive filters.
abstract: Retention of a two small phages (PhiX-174 and pp7) by direct-flow small-virus-retentive filters [Viresolve NFP (normal-flow parvovirus), Virosart CPV (canine parvovirus), Ultipor DV20 and Planova 20N] was studied using a commercial-process fluid. Phage passage occurred in each filter type, particularly when overloaded with phage. Clearances of pp7 and PhiX-174 were similar for any given filter brand, arguing that the two phages are equivalent for testing small-virus-retentive filters. The patterns of flux under constant pressure and instantaneous LRV (log reduction value) in relationship to cumulative phage load differed between brands, consistent with the current industry understanding that each brand possesses specific performance attributes. Phages are a powerful and universal tool for evaluating filter performance. Validation of filter performance with phages such as pp7 or PhiX-174 as models for small mammalian viruses represents an attractive alternative to the current practice.
authors.affiliation: Division of Monoclonal Antibodies, Office of Biotechnology Products, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Lute
authors.forename: Mark
authors.initials: M
authors.lastname: Bailey
authors.forename: Jessica
authors.initials: J
authors.lastname: Combs
authors.forename: Muppalla
authors.initials: M
authors.lastname: Sukumar
authors.forename: Kurt
authors.initials: K
authors.lastname: Brorson
mesh_terms: D001435:Bacteriophages / Q000302:isolation & purification*; D004340:Drug Contamination / Q000517:prevention & control*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D014462:Ultrafiltration / Q000295:instrumentation* / Q000379:methods*