Abstract

This paper presents a new scheme for monitoring the sequential loading of reagents to a detection site to conduct biological assays. The automation of the sequential loading of biological reagents to a detection site is monitored by a lens-less charged couple device (CCD). The fluid handling system employs a custom edge detection algorithm to determine the location of the channel edges. This custom edge detection method outperformed the built in Matlab edge detection functions. A parametric study was performed to determine the effects wavelength, height above a detection site, and voltage of a light emitting diode (LED), would have on the systems performance. A white light emitting diode, a voltage of 2.6V and a height of at least 20mm above the detection produced the best results. The fluid handling system was also able to work with channels that had different geometric designs and with different types of fluid. This research focuses for the first time on the monitoring of sequentially loading reagents to a detection site using a CCD imager that is also used for detection.

Keywords: Active fluid control, CCD, fluid handling, lab-on-chip, microfluidics, sequential loading.