The 'reverse capture' autoantibody microarray: a native antigen-based platform for autoantibody profiling

We have previously reported the development and the use of a 'reverse capture' autoantibody microarray for studies of antigen-autoantibody profiling. We developed the 'reverse capture' autoantibody microarray to allow the user to characterize and to compare autoantibody profiles. Based on the dual-antibody sandwich immunoassay of ELISA, our 'reverse capture' protocol facilitates the detection of autoimmunity to native host antigens. Our method has the advantage over traditional protein arrays of being able to detect autoimmunity to epitopes found on the post-translational modifications (PTMs) of native antigens. The first step of this method is to immobilize native antigens onto the monoclonal antibodies spotted on the array surface. Using the antigens captured by the microarray as 'baits,' we then incubate the array with differentially labeled IgG from test and control samples, and perform a two-slide dye-swap to normalize for dye effects. In this protocol we present a detailed description of the 'reverse capture' autoantibody microarray, a method that can be completed in 9-10 h over 1-2 d.