Nanocs iPEG™ PEG aldehyde is a N-terminus amine reactive PEG that can react with primary amine groups at pH 5-9. Unlike PEG NHS, aldehyde PEG can not only react with regular amine at alkaline condition, it can also react with N-terminus amine at pH 5-6.5. This is a site-specific amine pegylation reagent with bioconjugation control. Methoxy PEG aldehyde products from Nanocs include mPEG propionaldehyde,mPEG butyladehyde, mPEG benzaldehyde, these PEG aldehyde have high reactivity, narrow size distribution and high purity, your No. 1 choice for N-terminus pegylation reagents.