title: Cascade enzyme-linked immunosorbent assay (CELISA).
abstract: Immunoassays are representative biochemical detection methods. Among them, sandwich-type immunoassays, typified by sandwich ELISA, have used in disease diagnosis or biochemical detection with high target selectivity. Horseradish peroxidase and alkaline phosphatase have been typically used for signal amplification in ELISA. Recently developed sandwich-type immunoassays such as biobarcode immunoassays, immuno-PCR, and immuno-RCA have improved sensitivity by changing mainly the signal amplification method. To develop a novel amplification method in ELISA, an enzyme-cascading system was incorporated into an ELISA, and the new assay is termed a cascading enzyme-linked immunosorbent assay (CELISA). This CELISA includes a trypsinogen-enterokinase combination as the cascading enzyme system, and was used to detect alpha-fetoprotein (AFP), which is a liver cancer marker, and prostate-specific antigen (PSA). Using a colorimetric reagent for signal generation, CELISA had 0.1-10pM limits-of-detection for AFP and PSA in whole human serum and assay buffers, depending on the platform, well plate, or microbead type used. This study represents the first example that incorporated an enzyme cascading step in an ELISA system, resulting in successful signal amplification with sensitive detection of pathogenic antigens in serum.
authors: BioNanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Yuseong, Daejeon 305-333, Republic of Korea.
authors: Young-mi
authors: YM
authors: Lee
authors: Yujin
authors: Y
authors: Jeong
authors: Hyo Jin
authors: HJ
authors: Kang
authors: Sang J
authors: SJ
authors: Chung
authors: Bong Hyun
authors: BH
authors: Chung
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood*; D015374:Biosensing Techniques / Q000295:instrumentation*; D001774:Blood Chemical Analysis / Q000295:instrumentation*; D003124:Colorimetry / Q000295:instrumentation*; D004797:Enzyme-Linked Immunosorbent Assay / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D009363:Neoplasm Proteins / Q000097:blood*
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins