A synthetic glycoconjugate of BSA (neoglycoprotein) where the disaccharide Neu5Acα2-6GalNAc has been conjugated to BSA at multiple lysines by highly stable amide linkages via a discrete 9-atom triethylene glycol (PEG3) linker/spacer system functionalized with carboxylic acid. Neu5Acα2-6GalNAc is the carbohydrate component of the tumour associated cancer antigen, sialyl Tn or STn Antigen (Neu5Acα2-6GalNAcα-O-Thr/Ser).
