The use of monoclonal antibodies UCH beta and UCH gamma for the antenatal diagnosis of beta-thalassaemia.

Monoclonal antibodies for the beta-globin chain of human HbA (UCH beta) and the gamma-globin chain of human HbF (UCH gamma) have been made. UCH beta indirectly labelled with rhodamine-labelled goat anti-mouse Ig and directly flouresceinated UCH gamma have been used, via double labelling immunofluorescence microscopy, to assay for the presence of beta-chains in fetal erythrocytes obtained at fetoscopy from fetuses at risk for beta-thalassaemia major. The results from 111 cases demonstrate that beta-chain synthesis of as low as 1.8% can be detected in fetal erythrocytes. The immunochemical labelling can be rendered more sensitive by the use of biotinylated UCH beta and avidin-FITC conjugates. This method is rapid and can be used for a sample that is highly contaminated with maternal erythrocytes.