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ARRAY SERVICES


Science in Action has accumulated significant expertise in research and preparation (printing, scanning and analysis) of unique antigen arrays applied towards basic research and drug development.

Schematic representation of the antigen array:  The antigen arrays are used to detect the level of antibodies reactivity. Different antigens are attached to the chip surface (similar to the attachment of DNA segments in the case of DNA chips). When the array is exposed to serum the corresponding antibodies can attach to the antigens. The attachment is detected by exposure to marked (fluorescence) antibodies. Reactivity is measured according to the fluorescence level of each spot.

High Through-Put Array Screen:

Science in Action developed a novel High Through-Put Array (HTA) screen based on Micro-Array technology. In principle, peptides are exposed to a range of cytokines in micro-array on a custom-made slide. The unique conditions of Micro-Array facilitate the analysis of multiple cytokine-binding peptide-cytokine permutations and allow testing of a wide range of experimental conditions to optimize peptide-cytokine interaction. Up to one thousand samples (1-10ug/sample) can be assayed on one micro-array slide and eight to twelve slides are assayed per experiment. Compared with the standard ELISA screen (96 samples per plate, 100-1000ug/sample), micro-array allows for increased parameter range and enhanced detection sensitivity. Robotic sample preparation and manipulation ensure data reproducibility and reliability.

HTA, Micro-Array, "screening" identifies Peptides and Micro-Array “analysis” describes the unique disease associated protein (DAP) binding profile of each peptide. Given that each peptide is a potential modulator of DAP activity, peptides are candidates for manipulating the DAPs topological networks that underlie physiological immunity, the disruption of which correlates with autoimmune disease. The unique DAP binding profile of a peptide represents, therefore, a potential peptide-DAP regulatory “Supra-Network” for the control of disease-related protein in the networks. Each patient with an autoimmune inflammatory disease manifests a unique DAPs receptor expression pattern. The peptide-DAP regulatory Supra-Network provides the means to predict peptide-DAP interactions in a specific disease context and includes information for the exploitation of peptide-DAP interactions to treat patients on an individual basis – “personalized medicine”.

Phage Display HTA Screen:

Science in Action developed a proprietary technology for HTA screening of phage-displayed peptides against cytokines in micro-array. Peptides can now be screened prior to their chemical synthesis. Consequently, issues of peptide solubility and stability need only be addressed for those peptides that are active in the micro-array screen. Multiple peptide copies per phage particle, combined with high phage titer per sample, increase screening sensitivity orders of magnitude. HTA screen of phage-displayed peptides is efficient in terms of cost and time and effective in enhancing screening sensitivity and capacity. We have developed a proprietary technology to clone and display short peptides (9-15 amino acids) in recombinant phage.

The exceptionally small size of peptides and their short DNA-encoding sequences, pose formidable technical challenges for DNA cloning and peptide expression. We developed a proprietary technology for the directional cloning of short DNA fragments in phage and peptide display that surpasses the efficiency of commercially available kits (30%, 1-2 months cloning time). Oligonucleotide-directed peptide synthesis and in situ cloning by PCR increased cloning efficiency to 50%. Oligonucleotide design according to thermodynamic principles enhanced phage compatibility and raised cloning efficiency to 70%. Engineered oligonucleotides according to principles of host bacterial competence brought cloning efficiency to between 80 and 85% and cloning time to 10 days. This innovative technology, essential for lead discovery and optimization, is appropriate for any peptide, irrespective oforigin, or amino acid composition.