A Monolithic, Four-Colour Microfluidic Cytometer Optimized for Bead-Based Arrays

Posted by

Technology Networks

In order for point-of-care and on-site analysis to be realized, small, inexpensive and automated instruments must be made available. This also applies flow cytometry, which until recently has relied on quite large and expensive laboratory equipment. Unfortunately, the traditional sheath flow method does not lend itself well to microfabrication. A novel system for three-dimensional particle focusing will be presented that is robust, and easy to fabricate will be presented. The system has been incorporated into a microfluidic platform containing embedded optical fibers for optical illumination by two lasers and analysis at four wavelengths. Up to 13 sets of coded microspheres can be differentiated. The presence of targets is quantified using a phycoerythrin-bound tracer. Assays for such targets as Escherichia coli, Listeria, Salmonella, cholera toxin, staphylococcal enterotoxin B (SEB) and ricin have been demonstrated. Limits of detection ranges from 103 to 105 cfu/mL for the bacterial species, and 0.064 to 8.0 ng/mL for toxins.