Used to measure ALK (Anaplastic Lymphoma Kinase) enzyme activity in human cell lysates or tissue samples. Commonly applied in cancer research, especially for studying ALK-positive tumors such as non-small cell lung cancer and neuroblastoma. Helps evaluate the effectiveness of ALK inhibitors in drug development and monitors signaling pathway changes in clinical and preclinical studies. Provides a quantitative, high-throughput method for assessing phosphorylation levels of ALK and its downstream targets.