Fabrication of a microfluidic flow-through immunoassay for simultaneous detection of multiple cytokines
Nicole Y. Morgan (NIH/NIST), T.M. Phillips, T.J. Pohida, P.D. Smith (NIH); M. Gaitan (NIST/EEEL), L. Locascio (NIST/CSTL)
We have developed a chip-based microfluidic device for multi-analyte immunoaffinity capture and detection of proteins. The immediate motivation is an epidemiological study of the immune response to the Human Papilloma Virus (HPV), for which the simultaneous isolation of multiple proteins from microliter samples of cervical secretions is required. Using the microfabrication facilities at NIST, we are able to make micrometer-scale glass-encapsulated microfluidic systems with any desired two-dimensional configuration. The prototype devices consist of a long glass-encapsulated channel, 50 mm x 15 mm x 20 cm, with a serpentine pattern. Side ports are used for pressure-driven loading of different biotinylated antibodies into each segment of the channel; these antibodies bind to streptavidin that has been covalently linked to the channel walls. After the antibodies have been immobilized, the sample under analysis flows through the entire device. Electrical control of the sample flow permits adjustment of the residence time in each segment in order to optimize binding. The channel device architecture has several advantages over existing array technology: the proteins are detected by single-point capture, and much smaller sample volumes can be used. In addition, we hope to be able to reuse the channels with the bound antibodies for multiple samples.
Presenting Authorís information:
SigXi affiliation: associate member, UChicago chapter.
(NB ó I am a postdoc at NIH and a guest researcher at NIST)