%0 Journal Article %1 citeulike:797292 %A Stanley, C. J. %A Ellis, D. H. %A Bates, D. L. %A Johannsson, A. %C IQ(Bio) Ltd., Downham House, Downham's Lane, Milton Road, Cambridge CB4 1XG, England. %D 1987 %J J Pharm Biomed Anal %K nad immunoassay enzyme electrochemistry %N 8 %P 811--820 %T Enzyme-amplified immunoassays. %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16867457 %V 5 %X The sensitivity of enzyme immunoassays may be enhanced by the use of enzyme-amplification. This technique uses the enzyme label in the immunoassay to provide a trigger substance for a secondary system that can generate a large quantity of coloured product. Two examples of enzyme amplifiers are described, using either a substrate cycle with phosphorylated hexose sugars, or a redox cycle involving the coenzyme NAD(+). The redox enzyme-amplifier has a detection limit of less than one attomole for the enzyme label, alkaline phosphatase. The limited dynamic range of enzyme-amplified immunoassays may be overcome by kinetic analysis of the colour development in the enzyme-amplifier, to add at least a further order of magnitude to the range of directly measured analyte concentrations in the immunoassay. This is illustrated in an enzyme-amplified immunoassay for human thyroid stimulating hormone. Amperometric measurement of the enzyme-amplifier provides a method to extend the dynamic range still further and compares favourably with the performance of a gamma counter, a luminometer or a fluorimeter.

@article{citeulike:797292, abstract = {The sensitivity of enzyme immunoassays may be enhanced by the use of enzyme-amplification. This technique uses the enzyme label in the immunoassay to provide a trigger substance for a secondary system that can generate a large quantity of coloured product. Two examples of enzyme amplifiers are described, using either a substrate cycle with phosphorylated hexose sugars, or a redox cycle involving the coenzyme NAD(+). The redox enzyme-amplifier has a detection limit of less than one attomole for the enzyme label, alkaline phosphatase. The limited dynamic range of enzyme-amplified immunoassays may be overcome by kinetic analysis of the colour development in the enzyme-amplifier, to add at least a further order of magnitude to the range of directly measured analyte concentrations in the immunoassay. This is illustrated in an enzyme-amplified immunoassay for human thyroid stimulating hormone. Amperometric measurement of the enzyme-amplifier provides a method to extend the dynamic range still further and compares favourably with the performance of a gamma counter, a luminometer or a fluorimeter.}, added-at = {2006-08-15T16:48:47.000+0200}, address = {IQ(Bio) Ltd., Downham House, Downham's Lane, Milton Road, Cambridge CB4 1XG, England.}, author = {Stanley, C. J. and Ellis, D. H. and Bates, D. L. and Johannsson, A.}, biburl = {https://www.bibsonomy.org/bibtex/2345d6989aa2456d27650de5b1c6776e8/biblio24}, citeulike-article-id = {797292}, interhash = {5baddbe2d62acc545225888715643c9a}, intrahash = {345d6989aa2456d27650de5b1c6776e8}, issn = {0731-7085}, journal = {J Pharm Biomed Anal}, keywords = {nad immunoassay enzyme electrochemistry}, number = 8, pages = {811--820}, priority = {2}, timestamp = {2006-08-15T16:48:47.000+0200}, title = {Enzyme-amplified immunoassays.}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=pubmed\&dopt=Abstract\&list_uids=16867457}, volume = 5, year = 1987 }