We have developed a range of optical biochip devices for conducting live and fixed cell-based assays. The devices encompass the ability to process an entire assay including fluorescently labelling cells, a microfluidic system to transport and maintain cells to deliver them to an optical area of the device for measurement, with the possibility of a incorporating a sorting step in between. On-chip excitation provided by red emitting LED and lasers define the excitation wavelength of the fluorop...