Rapid, low-cost and instrument-free CD4+ cell counting for HIV diagnostics in resource-poor settings.

Authors:
Macdara T Glynn
Macdara T Glynn
Biomedical Diagnostics Institute
David J Kinahan
David J Kinahan
Dublin City University
Ireland
Dr. Jens Ducree, Dr. rer. nat. habil. Dipl. Phys.
Dr. Jens Ducree, Dr. rer. nat. habil. Dipl. Phys.
Fraunhofer Project Centre at Dublin City University
Professor (Full)
microfluidics, Lab-on-a-Chip, hydrodynanmics, business development, project management, organisational leadership
Glasnevin, Dublin 9 | Ireland

Lab Chip 2014 Aug 9;14(15):2844-51. Epub 2014 Jun 9.

Biomedical Diagnostics Institute, National Centre for Sensor Research, School of Physical Sciences, Dublin City University, Ireland.

We present a novel, user-friendly and widely autonomous point-of-care diagnostic to enable HIV monitoring in resource-poor regions where the current pandemic is most prevalent. To specifically isolate magnetically tagged CD4+ cells directly from patient blood, the low-cost and disposable microfluidic chip operates by dual-force CD4+ cell magnetophoresis; whereby the interplay of flow and magnetic fields governs the trajectory of target cells depending on whether the cell binds to a magnetic microbead. Instrument-free pumping is implemented by a finger-actuated elastic membrane; tagged beads are laterally deflected by a small and re-useable permanent magnet. The single-depth and monolithic microfluidic structure can easily be fabricated in a single casting step. After their magnetophoretic isolation from whole blood, estimation of CD4+ cell concentrations is then measured by bright-field inspection of the capture chamber. In addition, an optional fluorescence measurement can be used for confirmation of the bright-field result if required. On-chip CD4+ estimation produces a linear response over the full range of medically relevant CD4+ cell concentrations. Our technology combines high-efficiency capture (93.0 ± 3.3%) and cell enumeration.

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http://dx.doi.org/10.1039/c4lc00264dDOI Listing
August 2014
11 Reads
3 PubMed Central Citations(source)

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