Design and characterization of a compact dual channel virus counter

Abstract

Background: Although there is a growing need in the field of biotechnology to rapidly and accurately quantify viruses, time-consuming techniques such as the plaque titer method remain the ''gold standard.'' Flow cytometric methods for virus quantification offer the advantages of rapid analysis and statistical treatment. The technique presented in this work represents the first demonstration of a flow cytometric determination of a viral count that is directly related to the count obtained by plaque titer. Methods: A flow cytometric instrument for rapid quantification of virus particles was designed, constructed, and thoroughly characterized. A two-color method, which involved staining the viral genome and the protein coat for baculoviruses, was developed in addition to an algorithm to identify simultaneous events on the DNA and protein channels.

Antigenic composition of single nano-sized extracellular blood vesicles

“…Several attempts to overcome this limitation have been reported, including the use of single nanometric particle enumerators 24 , microfluidics-based cytometers 25 , and cytometers optimized to improve light scattering collection 26,27 . While these methods have confirmed the diversity of EV size and quantity 28,29 , in most cases they failed to address the compositional diversity of EVs.…”

Nanoparticle-based flow virometry for the analysis of individual virions

“…The exact tracing of virions to the cells that have produced them also requires the analysis of individual viral particles. Currently, the envelope composition of viruses is studied by analyzing viral preparations in bulk, although attempts to visualize viruses using flow cytometers have been made (5)(6)(7)(8)(9).…”

Evaluation of the Virus Counter® for rapid baculovirus quantitation

“…The instrument and assay represent a time and cost-effective alternative for determination of baculovirus concentration. While an early academic prototype using the same detection principle was presented previously by Stoffel et al (2005a), drastic improvements have since been made to produce a commercially available and viable instrument. These improvements have produced a system that is much more efficient, accurate and easy to use with a well-defined assay protocol.…”

“…This instrument is a substantially improved version of the original academic research instrument described previously by Stoffel et al (2005a). The addition of hydrodynamic focusing, a self-contained fluidics system and customized software for system control and data analysis has resulted in a commercially viable and available design.…”