Semi-quantitative determination of H type 1 and type 2 antigens on buccal epithelial cells and in saliva of secretors and non-secretors.

The amount of H antigens on buccal epithelial cells (BEC) of secretors and non-secretors was measured by flow cytometry. H type 1 and H type 2 on BEC were detected with fluorescein-labelled Ulex europaeus lectin, and H type 2 was measured with mouse monoclonal antibody. Between 3.5 and 6 times more H antigen was detected on cells from secretors compared with cells from non-secretors. The level of H type 2 was the same on BEC of secretors and non-secretors. Adsorption of H type 1 antigen from secretor saliva onto non-secretors BEC was demonstrated. A simple and sensitive ELISA method was developed for the determination of H in saliva with biotin-labelled Ulex lectin. This system provides a simple means for measuring the amount of H present in saliva and for the determination of secretor status.