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


     

Clinical Chemistry 19: 191-196, 1973;
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
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 Google Scholar
Google Scholar
Right arrow Articles by Helman, E. Z.
Right arrow Articles by Ting, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Helman, E. Z.
Right arrow Articles by Ting, P.

Clinical Chemistry, Vol 19, 191-196, Copyright © 1973 by the American Association for Clinical Chemistry

Counting of Beta and Gamma Emitters Used in Clinical Radioimmunoassays and Competitive-Binding Assays by Liquid Scintillation Counters

Edith Zak Helman 1 and Philip Ting 1

1 Radioimmunoassay Center, SID Applications Research, Beckman Instruments, Inc., 2500 N. Harbor Blvd., Fullerton, Calif. 92634.

Although liquid scintillation (LS) counters were originally designed to count low-energy beta emitting isotopes, they can also be used to count gamma emitters used in radioimmunoassay. This is made possible by placing the gamma emitter inside a "Microfuge" tube suspended from a LS vial cap into a scintillator fluid containing an electron density increaser. Efficiencies of 71% are obtained for 125I by this method, comparable to that obtained with Nal (TI) crystal gamma counters. Efficiencies for other clinically important isotopes used in radioimmunoassay—131I, 57Co, 60Co, 51Cr, 59Fe—by the Microfuge method are 15-19%; therefore, for these isotopes a LS "Mini-Vial" method is suggested, in which smaller volumes may be used. The dual capability of LS counters to count both beta and gamma emitters extends its usefulness in the clinical laboratory.


Key Words: diagnostic aid • cancer • beta and gamma counting • serum iron-binding capacity • "Microfuge" and "Mini-Vial" techniques • results with use of gamma counters compared • T3 test • digoxin measurement • cardiac disease • competitive binding • carcinoembryonic antigen

Submitted on July 3, 1972






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1973 by the American Association for Clinical Chemistry.