Microfluidic sedimentation cytometer for milk quality and bovine mastitis monitoring

Autor: Louise M. Barrett, Jose L. Garcia-Cordero, Antonio J. Ricco, Richard O'Kennedy
Rok vydání: 2010
Předmět:
Zdroj: Biomedical Microdevices. 12:1051-1059
ISSN: 1572-8781
1387-2176
DOI: 10.1007/s10544-010-9459-5
Popis: We report a rapid, low-cost, portable microfluidic sedimentation cytometer (SeCy) for assessing the somatic cell count and fat content of milk in 15 min using a “sample-in, answer-out” approach. The system consists of 12 independent microfluidic devices, essentially flattened funnel structures, fabricated on the footprint of a single plastic compact disc (CD). Each funnel structure holds 150 μL of milk, has an inlet for milk filling and an outlet for air to escape, and ends in a narrow, closed-end microfluidic channel that facilitates packing of the cells into a column whose length is proportional to cell count. The closed-end channel provides accurate cell counts over the range 50,000–>3,000,000 cells per mL. The assay separates cells and fat globules based on their densities (by differential sedimentation), concentrating white cells in the closed-end channel near the outer rim of the CD for estimation of total “cell pellet” volume, while fat globules move toward the center of disc rotation, forming a fat “band” in the funnel. After adding milk to two or more microfluidic devices, the CD is loaded onto a custom-built reader unit that spins the disc for 15 min. Two low-cost microscopes in the reader image the centrifuged cell pellet and the fat band, providing a sufficiently accurate cell count to diagnose mastitis and measuring fat content as an indication of health and nutritional status.
Databáze: OpenAIRE
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