Auristatin E Impurity 1 is supplied with comprehensive characterization data in accordance with regulatory guidelines. It is suitable for use in analytical method development, method validation (AMV), and quality control (QC) applications related to Abbreviated New Drug Applications (ANDA) or during the commercial manufacture of Auristatin. The product may serve as a reference standard, with additional traceability to pharmacopeial standards provided where feasible. This material is intended solely for analytical purposes and is not for human use.