TY - JOUR
T1 - The measurement of the isoflavone daidzein by time resolved fluorescent immunoassay
T2 - A method for assessment of dietary soya exposure
AU - Kohen, F.
AU - Lichter, S.
AU - Gayer, B.
AU - Deboever, J.
AU - Lu, L. J.W.
N1 - Funding Information:
This work was supported in part by a grant from Gesellschaft fur Biotechnologische Forschung mBH, Germany (F. K.) and by USPHS Grants CA 56273, CA65628, and AICR 95B119 (L. J. W.), and by NIH grant MO1-RR-00073 from the General Clinical Research Center, National Center for Research Resources. We are grateful to Mrs. M. Kopelowitz for secretarial assistance and to Wallac Oy, Turku, for the provision of equipment and reagents. The authors thank the nursing, dietary, and administrative staff of the General Clinical Research Center at the University of Texas Medical Branch, Galveston, for support of clinical research, Ann Livengood for designing research diet, Faith Einerson for computer and data management support, and Emily Thomas and Amy Nimmo for technical assistance.
PY - 1998/2/1
Y1 - 1998/2/1
N2 - We report a novel method for the measurement of urinary daidzein that is suitable for assessment of dietary soya exposure. The method incorporates the following features: (i) a highly specific monoclonal antibody to daidzein (clone 4E4) raised through the 7 position of daidzein and (ii) a europium labeled ovalbumin daidzein conjugate. In the present format, dilute urine samples of subjects who ingested soy milk are hydrolyzed with β-glucuronidase for 30 min on rabbit anti-mouse coated plants. Afterwards, the specific monoclonal antibody to daidzein, clone 4E4, and europium labeled ovalbumin daidzein conjugate are added. After 1 h incubation, the wall bound fluorescence of europium is measured by time resolved fluorescence and is inversely proportional to the concentration of daidzein over the range 0.1-10 ng daidzein/well. The method demonstrates good sensitivity, precision and comparability with the chemical method GC-FID. Unlike the chemical method, the present immunoassay technique for daidzein is applicable for the measurement of large amounts of samples in epidemiological studies of the assessment and monitoring of human exposure to soya food.
AB - We report a novel method for the measurement of urinary daidzein that is suitable for assessment of dietary soya exposure. The method incorporates the following features: (i) a highly specific monoclonal antibody to daidzein (clone 4E4) raised through the 7 position of daidzein and (ii) a europium labeled ovalbumin daidzein conjugate. In the present format, dilute urine samples of subjects who ingested soy milk are hydrolyzed with β-glucuronidase for 30 min on rabbit anti-mouse coated plants. Afterwards, the specific monoclonal antibody to daidzein, clone 4E4, and europium labeled ovalbumin daidzein conjugate are added. After 1 h incubation, the wall bound fluorescence of europium is measured by time resolved fluorescence and is inversely proportional to the concentration of daidzein over the range 0.1-10 ng daidzein/well. The method demonstrates good sensitivity, precision and comparability with the chemical method GC-FID. Unlike the chemical method, the present immunoassay technique for daidzein is applicable for the measurement of large amounts of samples in epidemiological studies of the assessment and monitoring of human exposure to soya food.
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U2 - 10.1016/S0960-0760(97)00156-8
DO - 10.1016/S0960-0760(97)00156-8
M3 - Article
C2 - 9605417
AN - SCOPUS:0031938158
SN - 0960-0760
VL - 64
SP - 217
EP - 222
JO - Journal of Steroid Biochemistry and Molecular Biology
JF - Journal of Steroid Biochemistry and Molecular Biology
IS - 3-4
ER -