Open AccessEnzyme inhibitory homogeneous immunoassay for high molecular weight antigen (II)
Author(s) -
Nishizono Isao,
Ashihara Yoshihiro,
Tsuchiya Hiromichi,
Tanimoto Tetsuji,
Kasahara Yasushi
Publication year - 1988
Publication title -
journal of clinical laboratory analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 50
eISSN - 1098-2825
pISSN - 0887-8013
DOI - 10.1002/jcla.1860020305
Subject(s) - immunoassay , homogeneous , enzyme , chemistry , antigen , inhibitory postsynaptic potential , antibody , biochemistry , immunology , medicine , mathematics , combinatorics
A sensitive homogeneous enzyme immunoassay for determination of high molecular weight antigens has been developed using thermophilic dextranase. The conjugate of dextranase with Fab' antibody fragment and insoluble blue dextran was prepared. Ferritin and α‐fetoprotein (AFP) were assayed using the conjugate and insoluble blue dextran. The assay procedure is as follows: sample is mixed with the conjugate and incubated at 37° C for 20 min. After addition of substrate, the mixture is incubated at arbitrary temperature for 30 min or 1 hr. Then enzyme reaction is terminated by addition of the stopper; and following centrifugation at 3000 rpm for 1 min the absorbance of the supernatant is measured. The measurable range of ferritin was from 8 to 200 ng/ml for AFP, it was 80‐3,000 ng/ml. The coefficients of correlation with radioimmunoassay (RIA) for ferritin and AFP were 0.971 and 0.987, respectively.