Wide-field Fluorescent Microscopy and Fluorescent Imaging Flow Cytometry on a Cell-phone

Hongying Zhu; Aydogan Ozcan

doi:10.3791/50451

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Method Article

Wide-field Fluorescent Microscopy and Fluorescent Imaging Flow Cytometry on a Cell-phone

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DOI:

10.3791/50451

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April 11th, 2013

Hongying Zhu¹ , Aydogan Ozcan¹^,²^,³

¹Electrical Engineering Department, University of California, Los Angeles , ²Bioengineering Department, University of California, Los Angeles , ³California NanoSystems Institute (CNSI), University of California, Los Angeles

Summary

We review our recent results on the integration of fluorescent microscopy and imaging flow cytometry tools on a cell-phone using compact and cost-effective opto-fluidic attachments. These cell-phone based micro-analysis devices might be useful for cytometric analysis, such as performing various cell counting tasks as well as for high-throughput screening of e.g., water samples in resource limited settings.

Abstract

Fluorescent microscopy and flow cytometry are widely used tools in biomedical research and clinical diagnosis. However these devices are in general relatively bulky and costly, making them less effective in the resource limited settings. To potentially address these limitations, we have recently demonstrated the integration of wide-field fluorescent microscopy and imaging flow cytometry tools on cell-phones using compact, light-weight, and cost-effective opto-fluidic attachments. In our flow cytometry design, fluorescently labeled cells are flushed through a microfluidic channel that is positioned above the existing cell-phone camera unit. Battery powered light-emitting diodes (LEDs) are butt-coupled to the side of this microfluidic chip, which effectively acts as a multi-mode slab waveguide, where the excitation light is guided to uniformly excite the fluorescent targets. The cell-phone camera records a time lapse movie of the fluorescent cells flowing through the microfluidic channel, where the digital frames of this movie are processed to count the number of the labeled cells within the target solution of interest. Using a similar opto-fluidic design, we can also image these fluorescently labeled cells in static mode by e.g. sandwiching the fluorescent particles between two glass slides and capturing their fluorescent images using the cell-phone camera, which can achieve a spatial resolution of e.g. ~ 10 μm over a very large field-of-view of ~ 81 mm². This cell-phone based fluorescent imaging flow cytometry and microscopy platform might be useful especially in resource limited settings, for e.g. counting of CD4+ T cells toward monitoring of HIV+ patients or for detection of water-borne parasites in drinking water.

Introduction

Microscopy and flow-cytometry are widely used techniques^1-12 in biomedical and scientific research as well as clinical diagnosis for counting and characterization of various cell types. However, conventional microscopes and flow-cytometry instruments are relatively complex and expensive, which limits their use to mainly well-established central laboratories. Recently we have developed a compact and lightweight fluorescent imaging cytometry and microscopy device integrated on a cell-phone,^13,14 which shows promise to cost-effectively translate fluorescent microscopy, flow-cytometry and related micro-analysis techniques to resource-limited environm....