Merrifield resin is widely used in solid-phase peptide synthesis (SPPS) as a solid support material. Its primary application lies in anchoring the growing peptide chain during the synthesis process, allowing for sequential addition of amino acids. The resin's insoluble nature enables easy separation and purification of the peptide from reagents and by-products through simple filtration. It is particularly valued for its stability under various reaction conditions and compatibility with a range of protecting groups and coupling reagents. Additionally, Merrifield resin is employed in combinatorial chemistry for the synthesis of small molecule libraries, facilitating high-throughput screening. Its versatility and efficiency make it a cornerstone in peptide and organic synthesis research.