Widely used in protein research for isoelectric focusing (IEF) to prepare protein samples before separation. It helps denature proteins, maintain solubility, and ensure uniform charge distribution, crucial for accurate analysis in 2D gel electrophoresis. The buffer often contains urea, thiourea, and detergents to disrupt protein interactions and prevent aggregation. It is essential for studying protein isoforms and post-translational modifications, providing insights into protein function and structure in proteomics research.