Protein Chip Based Miniaturized Assay for the Simultaneous Quantitative Monitoring of Cancer Biomarkers in Tissue Extracts

Proteomics. 2006 Mar;6(5):1427-36. doi: 10.1002/pmic.200500078.


A multiplexed fluorescence immunoassay using a novel planar waveguide technology-based microarray system, ZeptoMARK (Zeptosens), was developed to detect simultaneously urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor-1 (PAI-1), and vascular endothelial growth factor (VEGF) in extracts of breast cancer tissues. The three analytes assay was cross-validated with single-analyte ELISA/chemiluminescence immunosorbent assay tests, revealing good correlations and enhanced assay sensitivities (LODs) of 1 pg/mL for uPA, 33 pg/mL for PAI-1, and 1 pg/mL for VEGF. Values were well within the 80-120% limits for assay recovery and within the +/-20% limits for assay precision. The uPA, PAI-1, and VEGF results obtained from 50 breast cancer cytosols using the protein array system demonstrated that the microarray-based multiplexed assay is a sensitive and robust tool to be used for the simultaneous quantification of cancer markers in small breast cancer tissue samples (core biopsies). The miniaturized, multiplexed assay format has a potential to be used for the quantitative analysis of a larger set of validated markers with significance in disease management.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers, Tumor / analysis*
  • Breast Neoplasms / chemistry*
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Immunoassay / methods*
  • Plasminogen Activator Inhibitor 1 / analysis
  • Protein Array Analysis* / instrumentation
  • Protein Array Analysis* / methods
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Statistics as Topic
  • Tissue Extracts / chemistry*
  • Urokinase-Type Plasminogen Activator / analysis
  • Vascular Endothelial Growth Factor A / analysis


  • Biomarkers, Tumor
  • Plasminogen Activator Inhibitor 1
  • Tissue Extracts
  • Vascular Endothelial Growth Factor A
  • Urokinase-Type Plasminogen Activator