ABSTRACT
Our research group has been developing enzyme-linked immunosorbent assays (ELISA) microarray technology for the rapid and quantitative evaluation of biomarker panels. Studies using antibody microarrays are susceptible to systematic bias from the various steps in the experimental process, and these biases can mask biologically significant differences. For this reason, we have developed a calibration system that can identify and reduce systematic bias due to processing factors. Specifically, we developed a sandwich ELISA for green fluorescent protein (GFP) that is included on each chip. The GFP antigen is spiked into each biological sample or standard mixture and the resulting signal is used for calibration between chips. We developed ProMAT Calibrator, an open-source bioinformatics tool, for the rapid visualization and interpretation of the calibrator data and, if desired, data normalization. We demonstrate that data normalization using this system markedly reduces bias from processing factors. Equally useful, this calibrator system can help reveal the source of the bias, thereby facilitating the elimination of the underlying problem. ProMAT Calibrator can be downloaded at http://www.pnl.gov/statistics/ProMAT .
Subject(s)
Antibodies/analysis , Protein Array Analysis/methods , Proteomics/methods , Software , Antibodies/metabolism , Antigens/metabolism , Calibration , Enzyme-Linked Immunosorbent Assay/methods , Green Fluorescent Proteins/analysis , Green Fluorescent Proteins/chemistry , Logistic Models , Protein Array Analysis/standards , Proteomics/standardsSubject(s)
Antibodies/isolation & purification , Antigen-Antibody Complex , Extracorporeal Circulation/methods , Animals , Cytotoxicity, Immunologic , Extracorporeal Circulation/instrumentation , Humans , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Immunosorbents , Papio , Swine , Transplantation, HeterologousABSTRACT
Irrigation for agricultural purposes is one of the essential claims on available water resources. Those resources have not been adequately utilized in many countries for a variety of reasons. Where finance has been allocated to irrigation schemes, the schemes have tended to be large-scale, and the performance often disappointing. Alternatively, small-scale irrigation schemes, while receiving less support and encouragement, can often be more effective. For both large-scale and small-scale irrigation schemes, the responses of individual farmers and village communities are critical factors. More technologies need to be developed that are adapted to local needs, resources and aspirations within the context of current socio-economic practices. Obviously, the wider the range of technologies available, the more likely it will be that the technology most appropriate to existing conditions will be identified and used.
