Density-Gradient Mediated Band Extraction of Leukocytes from Whole Blood Using Centrifugo-Pneumatic Siphon Valving on Centrifugal Microfluidic Discs.

Authors:
David J Kinahan
David J Kinahan
Dublin City University
Ireland
Niamh A Kilcawley
Niamh A Kilcawley
Biomedical Diagnostics Institute
Philip L Early
Philip L Early
School of Physical Sciences
Agra | India
Macdara T Glynn
Macdara T Glynn
Biomedical Diagnostics Institute
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

PLoS One 2016 11;11(5):e0155545. Epub 2016 May 11.

School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland.

Here we present retrieval of Peripheral Blood Mononuclear Cells by density-gradient medium based centrifugation for subsequent analysis of the leukocytes on an integrated microfluidic "Lab-on-a-Disc" cartridge. Isolation of white blood cells constitutes a critical sample preparation step for many bioassays. Centrifugo-pneumatic siphon valves are particularly suited for blood processing as they function without need of surface treatment and are 'low-pass', i.e., holding at high centrifugation speeds and opening upon reduction of the spin rate. Both 'hydrostatically' and 'hydrodynamically' triggered centrifugo-pneumatic siphon valving schemes are presented. Firstly, the geometry of the pneumatic chamber of hydrostatically primed centrifugo-pneumatic siphon valves is optimised to enable smooth and uniform layering of blood on top of the density-gradient medium; this feature proves to be key for efficient Peripheral Blood Mononuclear Cell extraction. A theoretical analysis of hydrostatically primed valves is also presented which determines the optimum priming pressure for the individual valves. Next, 'dual siphon' configurations for both hydrostatically and hydrodynamically primed centrifugo-pneumatic siphon valves are introduced; here plasma and Peripheral Blood Mononuclear Cells are extracted through a distinct siphon valve. This work represents a first step towards enabling on disc multi-parameter analysis. Finally, the efficiency of Peripheral Blood Mononuclear Cells extraction in these structures is characterised using a simplified design. A microfluidic mechanism, which we termed phase switching, is identified which affects the efficiency of Peripheral Blood Mononuclear Cell extraction.

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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0155545PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4864222PMC
July 2017
4 Reads
5 PubMed Central Citations(source)
3.23 Impact Factor

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