Western Blot

Western Blot designates an analytical technique detecting specific proteins in complex samples through gel electrophoresis separation, membrane transfer, and antibody-based immunodetection, providing information about protein presence, molecular weight, relative abundance, and post-translational modifications. This fundamental method combines protein separation by size using SDS-PAGE, transfer onto membranes enabling antibody access, blocking preventing non-specific binding, primary antibody incubation recognising target proteins, and signal generation through chemiluminescence, fluorescence, or chromogenic substrates.

The biopharmaceutical industry employs Western blotting across research, development, and manufacturing applications. Target validation uses Western analysis confirming protein expression, phosphorylation states, or pathway activation. Mechanism of action studies employ the technique assessing drug effects on protein levels or modifications. Cell line characterisation confirms expression of recombinant proteins or absence of undesired proteins. Product characterisation employs Western blotting verifying identity, detecting degradation products, or assessing aggregation. Antibody specificity validation ensures therapeutic or diagnostic antibodies recognise intended targets without cross-reactivity. Quality control applications include detecting residual host cell proteins or confirming viral protein absence. Limitations include semi-quantitative nature, potential for antibody cross-reactivity, and sample preparation effects. As proteomics technologies advance offering more comprehensive protein analysis, Western blotting remains valuable for targeted protein detection and mechanistic studies providing visual confirmation of protein characteristics.