We describe the production and preliminary characterisation of a set of monoclonal antibodies (MAbs) raised against placental alkaline phosphatase (PLAP). Different forms of antigen presentation, PLAP or PLAP-like expressing whole cells, placental membranes or purified PLAP were used t o immunise BALB/c mice. Initial screening was carried out against the immunising material by ELISA, against fresh frozen placental sections by immunostaining and against purified PLAP using an enzyme capture assay. The most successful fusions were those following whole cell immunisation, producing 27 antibodies that all reacted with both the placental and testicular f o r m of enzyme. These all showed a broadly similar pattern of reactivity when tested against a range of human malignant cell lines. Further characterisation identified one antibody, 866, as strongly reactive with formalin-fixed paraffin-embedded placental sections. This antibody also performed well when tested against a range of normal and malignant routinely fixed tissue sections. Of 14 antibodies analysed for immunoglobulin isotype, 10 were of the lgGl subclass. In competitive binding studies with 7 antibodies t o discriminate epitopes, at least 4 distinct binding sites were identified. By Scatchard analysis on 4 of these antibodies, binding constants of 3 were within the range 3.5-5.3 x 10-9n. Unusually the 4th antibody appeared t o recognise 2 separate antigen sites with binding constants of 2.1 and 7.5 x IO-'n. I n a preliminary study to compare patterns of reactivity of a selection of the new antibodies with a limited number of sera from smokers and seminoma patients, results indicate their potential for further typing within the placental group of enzymes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.