The prognosis, diagnosis, monitoring, or therapy of many diseases—melanoma, breast cancer, HIV detection, liver diseases—relies on the results of an ELISA (Enzyme-Linked Immuno Sorbent Assay) test. Typically, ELISA is time consuming and tedious and involves mixing, incubation, and washing, all carried out on a 96-well microtiter plate.

To spice up that musty old procedure, Hongyan He and his colleagues at The Ohio State University have built an integrated microfluidic device on a compact disk (CD), which automatically performs some of the more tedious tasks of ELISA. Each step of the ELISA procedure corresponds to a subtle yet precise change in the rotation speed of the CD, so that the centrifugal force of the fluid through the microfluidic channels is carefully controlled. Combined with microfluidic capillary forces, the flow sequence is accurately controlled for the different solutions involved in the ELISA process. Dr. He's paper—just published in the current issue of Biomicrofluidics¹—focuses on a microfluidic biochip that is used to detect a cytokine IFN-γ, and theoretically the device can be used for additional immunoassay applications.

Dr. He and his team have been using the CD technology as a basis for other applications for several years now, but the new CD-based ELISA design was just published online in Biomicrofluidics¹, and builds off of several years of CD-based microfluidic research by Dr. He's and Dr. James Lee's team at OSU.²

¹He, H., Yuan, Y., Wang, W., Chiou, N., Epstein, A., & Lee, L. (2009). Design and testing of a microfluidic biochip for cytokine enzyme-linked immunosorbent assay Biomicrofluidics, 3 (2) DOI: 10.1063/1.3116665

²Lai, S., Wang, S., Luo, J., Lee, L.J., Yang, S.-T., and, Madou, M.J. (2004). Design of a Compact Disk-like Microfluidic Platform for Enzyme-Linked Immunosorbent Assay Analytical Chemistry 76 (7), 1832-1837 DOI: 10.1021/ac0348322