Biomedical subjects

E Delamarche

Publications and source records attributed to E Delamarche.

3 recordsLinked to original sources

PubMed2001

Micromosaic immunoassays.

Immunoassays are widely used for medical diagnostics and constitute the principal method of detecting pathogenic agents and thus of diagnosing many diseases. These assays, which are most often performed in well plates, would be greatly improved by a practical method to pattern a series of antigens on a flat surface and to localize their binding to many analytes. But no obvious method exists to expose a planar surface successively to a series of antigens and analytes. Here, we present miniaturized mosaic immunoassays based on patterning lines of antigens onto a surface by means of a microfluidic network (muFN). Solutions to be analyzed are delivered by the channels of a second muFN across the pattern of antigens. Specific binding of the target antibodies with their immobilized antigens on the surface results in a mosaic of binding events that can readily be visualized in one screening using fluorescence. It is thus possible to screen solutions for antibodies in a combinatorial fashion with great economy of reagents and at a high degree of miniaturization. Such mosaic-format immunoassays are compatible with the sensitivity and reliability required for immunodiagnostic methods.

Enzyme-Linked Immunosorbent Assay↗

PubMed2001

Affinity capture of proteins from solution and their dissociation by contact printing.

Biological experiments at the solid/liquid interface, in general, require surfaces with a thin layer of purified molecules, which often represent precious material. Here, we have devised a method to extract proteins with high selectivity from crude biological sample solutions and place them on a surface in a functional, arbitrary pattern. This method, called affinity-contact printing (alphaCP), uses a structured elastomer derivatized with ligands against the target molecules. After the target molecules have been captured, they are printed from the elastomer onto a variety of surfaces. The ligand remains on the stamp for reuse. In contrast with conventional affinity chromatography, here dissociation and release of captured molecules to the substrate are achieved mechanically. We demonstrate this technique by extracting the cell adhesion molecule neuron-glia cell adhesion molecule (NgCAM) from tissue homogenates and cell culture lysates and patterning affinity-purified NgCAM on polystyrene to stimulate the attachment of neuronal cells and guide axon outgrowth.

Animals↗

PubMed1997

Patterned delivery of immunoglobulins to surfaces using microfluidic networks.

Microfluidic networks (microFNs) were used to pattern biomolecules with high resolution on a variety of substrates (gold, glass, or polystyrene). Elastomeric microFNs localized chemical reactions between the biomolecules and the surface, requiring only microliters of reagent to cover square millimeter-sized areas. The networks were designed to ensure stability and filling of the microFN and allowed a homogeneous distribution and robust attachment of material to the substrate along the conduits in the microFN. Immunoglobulins patterned on substrates by means of microFNs remained strictly confined to areas enclosed by the network with submicron resolution and were viable for subsequent use in assays. The approach is simple and general enough to suggest a practical way to incorporate biological material on technological substrates.

Adhesiveness↗