Detection of ERG protein using ELISA. A. Evaluation of ERG antibody reactivity in the ELISA format. B. Capture and detection antibody combinations for development of antigen capture assay (sandwich ELISA). C. The limit of detection of purified recombinant ERG protein was 30 pg. D. The limit of detection of ERG protein from VCaP cell lysates (without mixing with LNCaP cells) was 10,000 cells.