Allergen diagnosis microarray with high-density immobilization capacity using diamond-like carbon-coated chips for profiling allergen-specific IgE and other immunoglobulins

The diagnosis of antibody-mediated allergic disorders is based on clinical findings, skin prick tests and detection of allergen-specific IgE in serum. Here, we present a new microarray technique of high-density antigen immobilization using carboxylated arms on the surface of a diamond-like carbon (DLC)-coated chip. High immobilization capacity of antigen on DLC chip at (0.94–7.82) × 109 molecules mm−2 allowed the analysis of allergen-specific immunoglobulins against not only purified proteins but also natural allergen extracts with wide assay dynamic range. The higher sensitivity of the allergen-specific IgE detection on DLC chip was observed for comparison with the UniCAP system: the DLC chip allowed lowering the limit of dilution rate in UniCAP system to further dilution at 4–8-fold. High correlations (ρ > 0.9–0.85) of allergen-specific IgE values determined by the DLC chip and UniCAP were found in most of 20 different allergens tested. The DLC chip was useful to determine allergen-induced antibodies of IgA, IgG, IgG1, and IgG4 in sera, apart from IgE, as well as secretory IgA in saliva against the same series of allergens on the chip in a minimal amount (1–2 μL) of sample.

. To improve protein microarray sensitivity and scope of measurements, we designed the high-density DNA solidification technique of the carboxylated diamond like carbon chip for the allergen microarray technique. High-density antigen immobilization accomplished high-sensitivity with wide dynamic range and throughput antibodies (IgE, IgA, IgG, IgG1, IgG4, saliva IgA) quantification by a minimal amount (1–2 μL) of sera and saliva.Figure optionsDownload as PowerPoint slideHighlights
► We develop a new allergen diagnosis microarray using a diamond-like carbon (DLC) chip.
► The DLC chip shows highest density of antigen immobilization in microarrays reported.
► The DLC chip measures allergen-specific IgE, IgA, and IgG quantitatively with high sensitivity.