EORTC Receptor and Biomarker Study Group report: A sandwich enzyme-linked immunosorbent assay for vascular endothelial growth factor in blood and tumor tissue extracts

A four-antibody sandwich enzyme-linked immunosorbent assay (ELISA) for vasc ular endothelial growth factor (VEGF) for application in blood (serum and p lasma) and tumor tissue extracts was set up within the framework of the EOR TC Receptor and Biomarker Study Group (RBSG). Polyclonal antibodies against VEGF(165) Were raised in chickens and rabbits, and used in a previously de scribed assay format. The assay was validated and characterized for use in serum, plasma and tumor tissue extracts. The resulting VEGF ELISA was found to be specific for VECF165 and VEGF(121), the main isoforms of VEGF. The a ssay showed good precision and parallelism in serial dilutions of samples. The assay was not susceptible to interference by heterophilic antibodies be cause avian antibodies (duck anti-chicken and chicken anti-VEGF) were used in the pre-analyte stage and mammalian antibodies (rabbit anti-VEGF and goa t anti-rabbit) in the post-analyte stage. In conclusion, a sensitive, robus t and specific VEGF ELISA has been developed. Research into the prognostic value of VEGF employing this assay is currently underway.