A cost effective non-commercial ECL-solution for Western blot detections yielding strong signals and low background

We compared several alternative ECL solutions for Western blot detection of endogenous proteins in whole cell lysates using inexpensive, commercially available reagents. Starting from an existing protocol based on p-coumaric acid (pCA) as enhancer, we found that the ECL solution containing 4-iodophenylboronic acid (41PBA) generated strong specific signals and low background chemiluminescence. We optimised the lummol, 41PBA and hydrogenperoxide concentrations of this 41PBA-ECL solution. The optimised 41PBA-ECL solution (100 mM Tris/HCl pH 8.8, 1.25 mM luminol, 2 mM 41PBA, 5.3 mM hydrogenperoxide) shows a greatly increased signal intensity compared to the initial pCA-ECL protocol and to some commercially available ECL solutions. In addition, the optimised 41PBA-ECL solution also generates much lower background chemiluminescence than other noncommercial ECL solutions using p-coumaric acid or 4-iodophenol as enhancers. The 41PBA-ECL solution was stable when stored but had the lowest background when prepared freshly from stock solutions. Thus, we present an optimised protocol for a well-performing inexpensive ECL solution which is an alternative to expensive commercial ECL solutions and which achieves a better signal and lower background than the commercial solutions tested. (c) 2006 Elsevier B.V. All rights reserved.