a plurality of IR-transmitting optical fibers, wherein said optical fibers each have a first end and a second end, and wherein said fibers are capable of transmitting infrared radiation (“IR”) generated during decoding of a protein via a binding interaction of the protein with a binding compound;

a sensor for sensing IR generated from the binding interaction, wherein said sensor is in IR-sensing contact with said first end of each of said optical fibers; and

a sliding separator, wherein said separator engages said plurality of fibers and is slideable therealong to alter a separation therebetween, wherein the alterable separation facilitates the engagement of the optical fibers with individual samples disposed in wells of any one of a variety of different-sized sample plates having different spacing between the wells.