title: HIV viral RNA extraction in wax immiscible filtration assisted by surface tension (IFAST) devices.
abstract: The monitoring of viral load is critical for proper management of antiretroviral therapy for HIV-positive patients. Unfortunately, in the developing world, significant economic and geographical barriers exist, limiting access to this test. The complexity of current viral load assays makes them expensive and their access limited to advanced facilities. We attempted to address these limitations by replacing conventional RNA extraction, one of the essential processes in viral load quantitation, with a simplified technique known as immiscible filtration assisted by surface tension (IFAST). Furthermore, these devices were produced via the embossing of wax, enabling local populations to produce and dispose of their own devices with minimal training or infrastructure, potentially reducing the total assay cost. In addition, IFAST can be used to reduce cold chain dependence during transportation. Viral RNA extracted from raw samples stored at 37°C for 1 week exhibited nearly complete degradation. However, IFAST-purified RNA could be stored at 37°C for 1 week without significant loss. These data suggest that RNA isolated at the point of care (eg, in a rural clinic) via IFAST could be shipped to a central laboratory for quantitative RT-PCR without a cold chain. Using this technology, we have demonstrated accurate and repeatable measurements of viral load on samples with as low as 50 copies per milliliter of sample.
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin. Electronic address: berry3@wisc.edu.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Berry
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin.
authors.forename: Alex J
authors.initials: AJ
authors.lastname: LaVanway
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin.
authors.forename: Hannah M
authors.initials: HM
authors.lastname: Pezzi
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin.
authors.forename: David J
authors.initials: DJ
authors.lastname: Guckenberger
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin.
authors.forename: Meghan A
authors.initials: MA
authors.lastname: Anderson
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Loeb
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin.
authors.forename: David J
authors.initials: DJ
authors.lastname: Beebe
mesh_terms: D001483:Base Sequence; D004867:Equipment Design; D005374:Filtration / Q000295:instrumentation* / Q000379:methods; D006678:HIV / Q000235:genetics / Q000302:isolation & purification*; D015658:HIV Infections / Q000175:diagnosis* / Q000821:virology; D006801:Humans; D057230:Limit of Detection; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013500:Surface Tension; D019562:Viral Load
chemical_list: D012367:RNA, Viral