Used as a reference standard in analytical laboratories to calibrate instruments and validate methods for the detection and quantification of indole-3-acetic acid (IAA) in environmental, plant, and biological samples. Commonly applied in high-performance liquid chromatography (HPLC), mass spectrometry (MS), and immunoassay techniques to ensure accurate measurement of IAA levels. Essential in plant physiology research for studying hormone distribution, metabolism, and regulation in growth and development. Also used in quality control of agricultural and phytochemical products where precise hormone concentration is critical.