Abstract: A method of identifying an analyte. The method includes providing a plurality of microparticles. The microparticles have optically detectable codes extending along bodies of the corresponding microparticle. The microparticles have the chemical probes attached thereto. Each of the chemical probes is associated with a corresponding one of the codes. The method also includes selectively binding target analytes to the chemical probes on the microparticles to produce labeled microparticles and distributing the labeled microparticles to random locations of a substrate. The method also includes determining the codes for the labeled microparticles in the random array and code positions of the codes in the random array. The method further includes detecting the label on the labeled microparticles in the random array and label positions of the labels in the random array. The method also includes using the code positions and the label positions to analyze the target analyte.

Abstract: A method and apparatus are provided for aligning optical elements or microbeads, wherein each microbead has an elongated body with a code embedded therein along a longitudinal axis thereof to be read by a code reading device. The microbeads are aligned with a positioning device so the longitudinal axis of the microbeads is positioned in a fixed orientation relative to the code reading device. The microbeads are typically cylindrically shaped glass beads between 25 and 250 microns (?m) in diameter and between 100 and 500 ?m long, and have a holographic code embedded in the central region of the bead, which is used to identify it from the rest of the beads in a batch of beads with many different chemical probes. A cross reference is used to determine which probe is attached to which bead, thus allowing the researcher to correlate the chemical content on each bead with the measured fluorescence signal.

Abstract: A method of manufacturing optical identification elements that includes forming a diffraction grating in a fiber substrate along a longitudinal axis of the substrate. The grating includes a resultant refractive index variation. The method also includes cutting the substrate transversely to form a plurality of optical identification elements that have the grating therein along substantially the entire length of the elements. Each of the elements has substantially the same resultant refractive index variation.

Abstract: Microparticles 8 includes an optical substrate 10 having at least one diffraction grating 12 disposed therein. The grating 12 having a plurality of colocated pitches ? which represent a unique identification digital code that is detected when illuminated by incident light 24. The incident light 24 may be directed transversely from the side of the substrate 10 with a narrow band (single wavelength) or multiple wavelength source, in which case the code is represented by a spatial distribution of light or a wavelength spectrum, respectively. The code may be digital binary or may be other numerical bases. The micro-particles 8 can provide a large number of unique codes, e.g., greater than 67 million codes, and can withstand harsh environments. The micro-particles 8 are functionalized by coating them with a material/substance of interest, which are then used to perform multiplexed experiments involving chemical processes, e.g., DNA testing and combinatorial chemistry.

Abstract: An optical identification element having a synthesized chemical attached thereto includes an optical substrate having at least one diffraction grating disposed therein, the grating having a resultant refractive variation at a grating location, said grating being embedded within a substantially single material of said optical substrate; the grating providing an output optical signal indicative of a code when illuminated by an incident light signal propagating in free space, the code identifying at least one of the element and the chemical, the output signal not being a result of laser action with the grating when illuminated by said incident light signal; and the synthesized chemical being attached to the substrate.

Abstract: A method and apparatus f or performing an assay process, featuring providing microbeads in a solution; placing the microbeads on an alignment substrate; reading codes of the microbeads and the position thereof on the alignment substrate; reading the fluorescence on each microbead and the position order thereof on the alignment substrate; and determining an assay result based on bead position order and bead code of the earlier reading steps, where the microbead is an encoded particle having a particle substrate; a portion of the substrate being made of a substantially single material and having at least one diffraction grating embedded therein, the grating having a resultant refractive index variation within the single material at a grating location; and the grating providing an optical output signal indicative of a code when illuminated by an incident light signal propagating from outside said substrate, the optical output signal being a result of passive, non-resonant scattering from said grating when illumi