The aberrant glycosylation profiles of mucin glycoproteins on epithelial tumour cells represent attractive target structures for the development of immunotherapy against cancer. Mucin-type glycopeptides have been successfully investigated as molecularly defined vaccine prototypes for triggering humoral immunity but are susceptible to rapid in vivo degradation. As a potential means to enhance the bioavailabilities of the antigenic structures, hydrolysis-resistant carbohydrate analogues with fluorine substituents at positions C6, C2' and C6' were synthesised and incorporated into the tandem repeat sequence of the mucin MUC1. The resulting pseudo-glycopeptides can be used to elucidate the effects of chemically modified antibody determinants on metabolic and immunological properties.