The Ubiquitin Proteasome System (UPS) regulates key cellular processes, including signaling, DNA repair, and protein degradation. Ubiquitin forms chains on seven lysines, with K48 and K63 linkages being especially important. K48 chains primarily drive proteasomal degradation, while K63 chains regulate trafficking, signaling, DNA repair, and protein protein interactions. LifeSensors’ K63 Ubiquitin Linkage ELISA Kit enables precise measurement of K63 ubiquitination in cell and tissue lysates under various conditions, replacing labor intensive Western blot methods. The assay provides quantitative, reproducible results and supports high throughput screening and SAR studies in drug discovery applications. The plate is for research use only.