Methods consuming small sample amounts and allow for sensitive screening of large numbers of putative biomarkers indicative of disease are required to advance biomarker discovery and validation. We present multiplex proximity ligation applied in a pilot study profiling plasma biomarkers in pancreatic and ovarian cancer. Four panels of 6- and 7-plex PLAs were used to detect biomarkers, with each assay consuming only 1 micro Litre plasma sample using either matched-monoclonal antibody pairs or single batches of polyclonal antibody with femto Molar sensitivity. Protein analytes were converted to unique DNA amplicons by proximity ligation and subsequently detected by quantitative PCR.
 The novel technology presented solves many analytical problems found in biomarker verification, such as sensitivity, multiplexing, throughput, and sample consumption. The results of the pilot study show potential improvements in ability to detect pancreatic cancer in biobanked samples using a multimarker analysis approach. Also, the technology can detect protein-protein interactions and use these as informative markers.

99th AACR Annual Meeting-- Apr 12-16, 2008; San Diego, CA