Clinical Chemistry AACC Online Job Center
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 QUICK SEARCH:   [advanced]


     


Clinical Chemistry 20: 783-789, 1974;
This Article
Right arrow Full Text (PDF)
Right arrow Submit an electronic Letter to
the Editor about this paper
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Jacobsen, J.
Right arrow Articles by Wennberg, R. P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Jacobsen, J.
Right arrow Articles by Wennberg, R. P.

Clinical Chemistry, Vol 20, 783-789, Copyright © 1974 by the American Association for Clinical Chemistry

Determination of Unbound Bilirubin in the Serum of Newborns

Jorgen Jacobsen 1 and Richard P. Wennberg 1

1 Department of Pediatrics, Division of Neonatal Biology, University of Washington, Seattle, Wash. 98195.

An enzymatic assay is described for non-albuminbound bilirubin in the serum of newborn infants. Unbound bilirubin is oxidized to colorless compounds by ethyl hydroperoxide in the presence of horseradish peroxidase (EC 1.11.1.7), while albumin-bound bilirubin is protected from oxidation. Because the equilibrium between albumin and bilirubin occurs rapidly, the oxidation step is rate limiting, and the initial oxidation velocity of total bilirubin is proportional to the unbound bilirubin concentration. By titrating serum with bilirubin in vitro, the association constant and binding capacity of high-affinity sites for albumin binding can be determined. Normal human serum albumin tightly binds 1 mole of bilirubin per mole of albumin (binding constant, 2-4 x 108 liter/mol). Although weaker secondary binding occurs, the unbound bilirubin fraction increases rapidly after the high-affinity binding sites are saturated. Compromised newborns may have a decreased apparent binding capacity and (or) binding affinity. The method can be used to assess the risk of a jaundiced infant for bilirubin encephalopathy.


Key Words: bilirubin encephalopathy • free and bound bilirubin • binding affinity and capacity • perinatal chemistry • effects of drugs • kernicterus • erythroblastosis • enzymatic assay

Submitted on January 24, 1974
Accepted on May 3, 1974




The following articles in journals at HighWire Press have cited this article:


Home page
Arch. Dis. Child. Fetal Neonatal Ed.Home page
C V Hulzebos, D E van Imhoff, A F Bos, C E Ahlfors, H J Verkade, and P H Dijk
Usefulness of the bilirubin/albumin ratio for predicting bilirubin-induced neurotoxicity in premature infants
Arch. Dis. Child. Fetal Neonatal Ed., September 1, 2008; 93(5): F384 - F388.
[Abstract] [Full Text] [PDF]


Home page
PediatricsHome page
J. C. Sinclair
A Difference in Mortality Rate and Incidence of Kernicterus Among Premature Infants Allotted to Two Prophylactic Antibacterial Regimens, by William A. Silverman, et al, Pediatrics, 1956;18:614-624
Pediatrics, July 1, 1998; 102(1): 225 - 227.
[Abstract] [Full Text]


Home page
CLIN PEDIATRHome page
T. W. R. Hansen
Bilirubin in the Brain: Distribution and Effects on Neurophysiological and Neurochemical Processes
Clinical Pediatrics, August 1, 1994; 33(8): 452 - 459.
[PDF]


Home page
CLIN PEDIATRHome page
A. F. Robertson, W. B. Karp, H. C. Davis, W. Zack Catterton, and C. Bunyapen
Predicting the Need for Exchange Transfusion in Newborn Infants: A Comparison of Five Methods
Clinical Pediatrics, August 1, 1983; 22(8): 533 - 536.
[Abstract] [PDF]




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1974 by the American Association for Clinical Chemistry.