Ayoxxa Biosystems

Microarrays are built of an 8 cm x 2 cm silicon base plate, or biochip, with dozens of separate 'wells' or containers located on top, each one offering a capacity for up to 20 uL used to incubate with reagents, blocking or washing solutions. Each of these macro-wells, contain thousands of micro-wells at the bottom, each measuring about 1/20th the diameter of a single strand of human hair.[8][26][28]

The wells on the chip are filled with antibodies (proteins) linked to microspheres to reside in the cavities.[5][7][8] Antibodies by nature are produced by immune cells. They 'bind' specifically to the antigens on the surface of viruses, bacteria, and diseased cells to clear and to prevent health damages to the body. Since antibodies are highly specific proteins, binding to specific antigens, they have been exploited to identify and measure protein biomarkers in immunoassays (e.g. ELISA).[28]

Since different antibodies 'bind' themselves to antigens, this affinity can be exploited for protein analytics by filling the wells with thousands of antibodies, and observing if and how much of a target antigen is present in a sample, or not. Ayoxxa's biochip can be used to identify thousands of different proteins in a single sample, including markers for diseases, where before numerous of the classic ELISA assays would be required to achieve the same results.[3][7][10]

Microscopic photograph of microbeads. These are polymer nanoparticles, typically 0.5 to 500 micrometres in diameter. In protein laboratory work, researchers attach different antibodies to different beads, keeping a record of what specific type of antibody each bead contains, and then track those beads in order to observe which ones react when exposed to a sample.

To observe the reaction of the different antibodies to the sample, the chip is placed under a standard laboratory fluorescent microscope with a digital camera, which snaps shots of it. It is then possible to electronically analyze and generate data of the different molecules and proteins present in the samples.[1][23]

The technology centers on the patented In-situ Encoded Bead-based Arrays (IEBA),[29][30] originally developed at the National University of Singapore (NUS), of which Ayoxxa was made the exclusive licensee.[1][3][8] Unlike other available bead-based microarrays, IEBA achieves greater multiplexing capability by recording the position of randomly distributed beads without the need for physical labels for bead identification, using instead the assignment of unique coordinates to each bead with an in-house software.[10][23][25][26]

These batches of different beads, each batch being an assay or capture site for a specific biomolecule, are applied sequentially creating a unique pattern for every well. The coordinates of each individual bead in each sequential batch is recorded in a large map/decoding data table that is provided to the user alongside the carrier (like a USB flashdrive). The assay itself follows the sandwich ELISA principle with a read out based on a fluorescent reporter introduced at the final step of the assay. Following imaging using fluorescence microscope technology on the reacted chip, the company's analysis software identifies the individual beads according to their unique signals, later decrypted with the company's software to deliver a customized report to the user.[23][26] This approach significantly reduces the complexity of downstream analysis while increasing the number of individual protein targets that can be analyzed in very low sample volumes.[10][23][25]

Ayoxxa has stated that its focus is in developing an open and adaptable IEBA platform, that can be easily incorporated into laboratories by being compatible with the existing laboratory technology that researchers are accustomed to using. Furthermore, IEBA is being developed to run with automated liquid handling systems used in high-throughput screening. It has also stated its aim at making the IEBA an open platform, adaptable to the diverse research needs.[25][26] Ayoxxa's CEO Andreas Schmidt compared the company's open platform philosophy as that of iTunes and iPhone, where many different apps (different biomarkers) run on the iPhone (Ayoxxa’s platform).[7]

The IBEAs can be used from low sample numbers up to the standard 384 well plate format, basically being a more advanced ELISA, keeping the current standards and protocols.[23][25][26] The arrays are designed to be readily adaptable to standard high throughput screening systems.[10][25] The IEBA technology can be used with existing bioassays protocols (particularly the bioassays on beads), and readers without the need to invest in a flow cytometer or other capital-intensive devices to read it out.[25][26]