Used to measure Syk (spleen tyrosine kinase) enzyme activity in human cell lysates or tissue samples. Widely applied in immunology and cancer research to study signaling pathways in immune cells, especially in B cells and macrophages. Helps evaluate the effect of drug candidates on Syk activation in inflammatory diseases, autoimmune disorders, and hematological malignancies. Enables high-throughput screening in drug development and supports biomarker validation in clinical studies.