Enzyme immunoassay for conjugated cholic and 1 beta-hydroxycholic acids in urine of early infancy.
A direct competitive heterologous enzyme immunoassay (EIA) for conjugated cholic acid (CA) was developed using horseradish peroxidase labeled antigen having a shorter bridge length than that of the immunogen. An appropriate dose-response curve for conjugated CA was obtained in the range of 0.05-50 ng/well. Specificity of the EIA proved satisfactory in terms of cross-reactivities to 23 kinds of related bile acids. The proposed method was evaluated to be useful for the determination of conjugated CA in urine with acceptable accuracy and inter- and intra-assay precision. The results of analysis showed a reverse relationship between age and urinary excretion ratio of conjugated 1 beta-hydroxy-CA to conjugated CA in the first 9 months after birth.
Ikegawa
S
S
Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Japan.
Kinoshita
A
A
Kido
K
K
Murai
T
T
Yoshimura
T
T
Tohma
M
M
D001647:Bile Acids and Salts / Q000652:urine; D001667:Binding, Competitive; D019826:Cholic Acid; D002793:Cholic Acids / Q000652:urine*; D003429:Cross Reactions; D006801:Humans; D007124:Immunoenzyme Techniques; D007223:Infant; D007231:Infant, Newborn
D001647:Bile Acids and Salts; D002793:Cholic Acids; C035924:1,3,7,12-tetrahydroxycholanoic acid; D019826:Cholic Acid