Used in biomedical research to measure levels of activated c-Jun amino-terminal kinase (JNK) in rat tissue samples or cell lysates. This ELISA kit enables researchers to quantify phosphorylated JNK, which is critical for studying cellular stress responses, inflammation, apoptosis, and signaling pathways involved in diseases such as neurodegenerative disorders, diabetes, and cancer. It is commonly applied in preclinical studies to evaluate the effects of drugs or experimental treatments on JNK pathway activation in rat models. The assay provides a sensitive and specific method for high-throughput analysis of JNK activity, supporting mechanistic investigations in molecular and cellular biology.