Abstract
Western blotting is a ubiquitous tool used in protein and molecular biology research, providing information about the presence, size, relative abundance, and state of a protein in a mixture. First, the proteins in a sample are separated by size using SDS-PAGE then transferred onto a membrane for detection with a set of primary and secondary antibodies. High-quality Western data requires high signal-to-noise ratios, which depend upon reduction of nonspecific antibody interactions. Blocking is a critical step in the Western blot method as it prevents the antibodies from binding nonspecifically to the membrane and irrelevant proteins. A solution of nonfat dry milk (NFDM) in physiological buffer is commonly used for this purpose, but does not perform well with every type of antibody and is not optimal for low-abundance proteins. We present a novel blocking solution for chemiluminescent Western blots, AdvanBlock™-chemi, which outperforms NFDM in experiments with 20 unique antibodies by increasing signal-to-noise ratios and minimizing nonspecific binding. This solution enhances protein detection by Western blot and provides consistent results for detection of low abundant and modified proteins.