Western Blotting a review: Principle, protocol and problem solving

Western blotting is a fundamental technique widely used in molecular biology and biochemistry to quantify protein expression levels and modifications in various biological samples. This study presents a detailed protocol for performing WB, focusing on the principles and steps involved in the process. The article discusses the isolation of protein samples from cultured cells and their quantification using the BCA protein assay. The importance of protein quantification is emphasized to ensure accurate loading of proteins in gel wells. A step-by-step guide is provided for gel electrophoresis, highlighting the preparation of resolving and stacking gels and the migration of proteins under an applied voltage. Furthermore, the blotting procedure is detailed, covering membrane selection and the electrophoretic transfer process. The use of blocking agents to prevent non-specific antibody binding is explained, along with the incubation of primary and secondary antibodies. The article emphasizes the significance of negative and positive controls to validate the experimental results. Lastly, common troubleshooting strategies are provided to address potential issues encountered during the Western blotting process, such as absent or weak bands, unusual patterns, and high background. In conclusion, this comprehensive Western blotting protocol offers researchers a reliable and optimized method to analyse protein expression and modifications accurately, contributing to the advancement of molecular biology and biological research.