Microfluidic technologies for capturing and concentrating human immunodeficiency virus-1 (HIV-1) particles.

Abstract

HIV-1 RNA assays are routinely used in developed countries to monitor the effectiveness of antiretroviral therapy (ART). These assays require well-trained operators, expensive equipment and reagents, and established laboratory infrastructure. These requirements limit their usefulness in resource-limited settings where people are most afflicted by the HIV-1 epidemic. Recent advances in microfluidics and nanotechnology offer new approaches for rapid, low-cost, robust and simple HIV-1 viral load monitoring systems. Here we describe an approach within a microfluidic device to directly detect HIV-1 virus particles using an immune sandwich assay that includes anti-gp120 antibodies -conjugated to polystyrene microspheres and fluorescently labelled goat anti-HIV-1 FITC detection antibodies. The anti-gp120 antibody-conjugated microspheres were employed to capture and concentrate HIV-1 particles, whereas the FITC detection antibodies were used to generate fluorescent signal that represented the number of captured viruses. In the presence of HIV-1 particles, addition of microspheres and FITC detection antibody led to the formation of a microsphere/HIV-1 particle/FITC detection antibody complex. This complex was measured by analysing the fluorescence intensity produced by the FITC detection antibody bound to the HIV-1 particle within the complex. We demonstrated the utility of an in-house microfluidic device and assay in detecting 1x106 virus particles/μl with a significance of (p≤0.01). This assay was completed within 3.8 hours, without any pre- or post- treatment of reagents.