2,5-Dioxopyrrolidin-1-yl 19-(2,5-dioxo-2H-pyrrol-1(5H)-yl)-17-oxo-4,7,10,13-tetraoxa-16-azanonadecan-1-oate(Mal-amido-PEG4-NHS ester), 99%

*This document is like a lab demo—an example Certificate of Analysis (COA) that showcases what a COA looks like but may not match the latest batch in all its glory. Think of it as a chemistry experiment: close, but not quite the final reaction!