Figure 2.

Antibody microarray methods to profile proteins, autoantibody-antigen complexes and glycan modifications. Our antibody arrays contain ~3,200 distinct antibodies printed in triplicate along with control spots. (A) The proteins in the sample are quantified on the array after removal of IgG and albumin followed by direct labeling with Cy5 and incubation on the array with a Cy3 labeled reference sample as an internal control; (B) The same antibody array platform has been successfully implemented to detect autoantibody-antigen complexes and (C) glycoproteins modified with a specific glycan of interest. Essentially, the array performs affinity fractionation to purify the proteins to the ~3,200 specific spots on the array. Then, the bound proteins are probed with either a fluorescently labeled antibody specific to human IgG for autoantibody-antigen complex detection or to the cancer modified carbohydrate such as sialyl Lewis A (the CA19-9 antigen).