A PDMS-based disposable microfluidic sensor for CD4+ lymphocyte counting

Sara Thorslund*, Rolf Larsson, Jonas Bergquist, Fredrik Nikolajeff, Javier Sanchez

*Corresponding author for this work

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

A refined sensor for CD4+ lymphocyte count was developed and evaluated by comparison to flow cytometry. The micropillar structured sensor surface was cast in PDMS polymer and surface modified to gain biocompatibility and CD4-cell capturing properties. The sensor works by pure capillary action and sample filling and rinsing is performed without external equipment. Whole blood samples showed acceptable agreement (79%) with flow cytometry, however when diluting the blood in PBS buffer we discovered that a larger number of cells were drawn into the sensor microchannel compared to the initial sample, explained by enhanced shear-induced cell migration. Using plasma or PBS with glycerol or albumin additives as diluting media greatly influenced this cell behavior, showing the importance of controlling the dilution media when working with devices based on capillary filling. The sensors need to be further tested with blood samples with lower CD4-counts (<500 cells/ μl), which are clinically relevant.

Original languageEnglish
Pages (from-to)851-857
Number of pages7
JournalBiomedical Microdevices
Volume10
Issue number6
DOIs
Publication statusPublished - 2008

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Keywords

  • Capillary wetting
  • CD4 count
  • Dilution media
  • HIV monitoring
  • Point-of-care

Cite this

Thorslund, S., Larsson, R., Bergquist, J., Nikolajeff, F., & Sanchez, J. (2008). A PDMS-based disposable microfluidic sensor for CD4+ lymphocyte counting. Biomedical Microdevices, 10(6), 851-857. https://doi.org/10.1007/s10544-008-9199-y