Microtiter Based Planar Arrays

Glass slide-based immunoassay microarrays have been adapted to the microti-ter plate format to increase throughput and to use existing automated solutions. Although this limits the number of microspots available per well, it helps to avoid the problem of antibody-antibody interactions. Such an approach was adapted by Thermo Scientific with their SearchLight Protein Array Technology. On the bottom of each microtiter well, an array consisting of up to 16 microspot features are generated, which allows the measurement of 16 analytes from 50 ^L of sample. After incubation with sample, the wells are washed as with an ELISA and the captured antigen visualized using a secondary antibody labeled with a chemiluminescent probe. Quantitation of captured analytes is provided by a CCD imaging system using a calibration curve set up in parallel wells (www.piercenet.com).

Meso Scale Discovery (http://www.meso-scale.com) also uses a microtiter well microarray strategy called Multi-Array. Each well is arranged with 1 to 25 carbon microspots that are in essence miniature electrodes integrated into the bottom of the plate. Onto each carbon electrode the capture antibodies are immobilized, which after multiplexed immunoassay development results in a bound electrochemiluminescent (ECL) label. Quantitation of each assay is performed by passing electrical current through each electrode, producing a luminescent signal which is detected by a CCD camera imaging system. The microtiter plate format allows the use of standard liquid-handling automation with a multiplexed control and calibration strategy. As each Multi-Array plate can be imaged across all 96 wells within a few seconds, the sample throughput of this approach is large and quite scalable. The ECL detection system is also thought to provide significantly better sensitivity for immunoassays than can be provided by chemiluminescence or fluorescence.

The two planar array systems described above are typically operated in a manual mode, although both are capable of interfacing with automated liquid-handling systems. One fully automated planar array system in the marketplace is the Evidence, an automated biochip system developed by Randox Laboratories (http://www.randox.com). It provides multiplexed analysis of miniaturized and parallelized immunoassays in a macroarray format. This macroarray contains 25 features and uses a chemiluminescence-based readout. Several immunoassays panels are available, including fertility, cardiac disease, tumors, cytokines and growth factors, and drug residue panels.

Project Management Made Easy

Project Management Made Easy

What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.

Get My Free Ebook


Post a comment