Antibody microarrays utilizing site-specific antibody-oligonucleotide conjugates.

Protein arrays are typically made by random absorption of proteins to the array surface, potentially limiting the amount of properly oriented and functional molecules. We report the development of a DNA encoded antibody microarray utilizing site-specific antibody-oligonucleotide conjugates that can be used for cell immobilization as well as the detection of genes and proteins. This technology allows for the facile generation of antibody microarrays while circumventing many of the drawbacks of conventionally produced antibody arrays. We demonstrate that this method can be used to capture and detect SK-BR-3 cells (Her2+ breast cancer cells) at concentrations as low as 10(2) cells/mL (which is equivalent to 10 cells per 100 μL array) without the use of microfluidics, which is 100- to 10(5)-fold more sensitive than comparable techniques. Additionally, the method was shown to be able to detect cells in a complex mixture, effectively immobilizing and specifically detecting Her2+ cells at a concentration of 10(2) SK-BR-3 cells/mL in 4 × 10(6) white blood cells/mL. Patients with a variety of cancers can have circulating tumor cell counts of between 1 and 10(3) cells/mL in whole blood, well within the range of this technology.