Anti-FITC monoclonal antibody, clone MP-GMVP-2

Celiac disease is an autoimmune disorder represented by the ingestion of the gluten protein usually found in wheat, barley and rye. To date, ELISA has been the most accurate method for determining the presence of anti-gliadin, which is cumbersome, expensive (compared to a suspension microarray technique), and requires extensive sample preparation. In this study, in order to establish a more accurate assay to identify gliadin at lower concentrations, optical nano biosensors using an indirect immunoassay method for gliadin detection was designed and fabricated. For this, polycaprolactone (PCL) nano- to micro-beads were fabricated as a platform for the gliadin antigen which were optimized and nano functionalized with amine groups for such purposes. The gliadin antibody, which is selective to gliadin, was then added to the beads. Static light scattering tests were conducted to determine PCL particle size distribution and sizes were found from 0.1 to 30 mu m, which is suitable for flowcytometry detection devices. Anti-gliadin detection was performed using an anti IgG mouse antibody conjugated with FITC in a flow cytometry device to detect the smallest particle. Fluorescence intensity was investigated at different concentrations of anti-gliadin and a standard curve used to determine gluten concentration based on fluorescence intensity. Results showed that the fluorescence intensity increased with greater concentrations of anti-gliadin providing a very effective method of detection due to selectivity at a 5 ppm detection limit. This represents a new highly sensitive and fast method for anti-gliadin detection. Further, the disuse of a cross linker and the use of a dedicated antibody at a very low level (1 mu l) made this new method very economical to identify anti-gliadin concentrations at the nano level. In summary, this study provides a new, more accurate and sensitive, as well as less expensive system to detect anti-gliadin for the improved diagnosis of celiac disease.

Biomimetic synthesis of gold nanoparticles (GNPs) is critical in biomedical applications. Gold bioconjugates were fabricated by capping the water-dispersible gold-carbon nanoparticles with tyrosine, tryptophan and cysteine amino acids. Incubation of the water-soluble and easily reducible aryldiazonium gold(III) salt [HOOC-4-C6H4N equivalent to N]AuCl(4)with amino acids at room temperature formed a purple color over a few minutes with tryptophan and tyrosine and over two hours with cysteine. Rarely that cysteine is capable of reducing gold(III) precursors; however, a cysteine capped gold bioconjugate was synthesized and characterized in this study. Capping GNPs with amino acids was confirmed by high resolution transmission electron microscopy (TEM) and agarose gel electrophoresis. Depending on the amino acid, synthesized particles size was 27.2 +/- 5.4 nm, 14.6 +/- 7.7 nm and 8.6 +/- 2.6 nm for tyrosine, tryptophan and cysteine, respectively. The amino acids capped GNPs showed negligible cytotoxicity to human dermal normal fibroblast cell lines. The highly water dispersible bioconjugates were studied for in vitro cellular uptake by HeLa cancer cells using confocal laser scan microscopy (CLSM) after being labelled with FITC (GNPs-COOH-FITC) and the nuclei were counter stained with DAPI fluorescent dyes. The biomimetic route for the synthesis of the amino acids reduced gold-carbon nanoparticles will benefit the applications in biomedical devices and biosensors.