Used in plant biology research to quantify levels of cinnamic acid-4-hydroxylase (C4H), an enzyme involved in the phenylpropanoid pathway. This kit enables researchers to study lignin and flavonoid biosynthesis, which are critical for plant cell wall structure, UV protection, and defense mechanisms. By measuring C4H activity, scientists can assess plant responses to environmental stresses such as pathogen attack, wounding, or light exposure. It is also applied in genetic studies to evaluate gene expression and enzyme function in transgenic or mutant plants. The assay supports high-throughput analysis in agricultural and biochemical research aiming to improve crop resilience and secondary metabolite production.