Many labs wish to measure cytokines in an accurate, reproducible, and rapid manner. An antibody-based membrane array for measuring cytokines has been developed based on the same technology as the traditional ELISA. The aim of this study was to compare results obtained with the traditional ELISA method with those from the membrane array technology, a form of low-cost proteomics. Diluted human whole blood was stimulated with live bacteria (Escherichia coli, or Staphylococous aureus), or LPS and cytokines were measured both by ELISA and the membrane protein array. Of the 16 cytokines measured via ELISA, only IFN-gamma was below detection level. The other 15 cytokines were present in concentrations up to several thousand picograms/ml. Of the 20 cytokines measured via membrane protein array, only 3 could be detected (IL-6, IL-8 and MIP-1beta). Additionally, the membrane protein array did not detect TNF-alpha from the LPS-stimulated blood. These results indicate that the low-cost membrane protein array may lack sufficient sensitivity to adequately detect cytokines levels in complex biological fluids such as human plasma. (C) 2003 Elsevier B.V. All rights reserved.