Heterogeneous enzyme immunoassay with electrochemical detection: competitive and "sandwich"-type immunoassays.
In these competitive and "sandwich"-type heterogeneous enzyme immunoassays, based on liquid chromatography with electrochemical detection, rabbit immunoglobulin G is used as a model compound. Alkaline phosphatase (EC 3.1.3.1), the labeling enzyme, catalyzes conversion of phenyl phosphate to phenol. After separation on an octyldecylsilane column, the enzyme-generated phenol is detected in a thin-layer cell at a carbon-paste working electrode. The detection limit for phenol is 5.0 nmol/L. The electrode response varies linearly with concentration over a range of three orders of magnitude. For the sandwich-type assay procedure the detection limit is 10 ng/L; the linearity ranges over four orders of magnitude. The detection limit of the competitive immunoassay is 5 micrograms/L. The dynamic range spans two orders of magnitude.
D000469:Alkaline Phosphatase; D000818:Animals; D002021:Buffers; D002853:Chromatography, Liquid; D004563:Electrochemistry; D007124:Immunoenzyme Techniques; D007074:Immunoglobulin G / Q000032:analysis; D011817:Rabbits
D002021:Buffers; D007074:Immunoglobulin G; D000469:Alkaline Phosphatase