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Internal sample attenuator counting (ISAC). A new technique for separating and measuring bound and free activity in radioimmunoassays

Journal Article · · Clin. Chem. (Winston-Salem, N.C.); (United States)
OSTI ID:5799416
A new method for the separation counting of bound and free activity in radioimmunoassays is described. Particles containing a radiation-abosrbing (attenuating) material are added to the assay. They shield the radiation from either the antibody-bound or the free radioligand. This obviates such manipulations conventionally involved in the separation and counting steps of radioimmunoassays as centrifugation decanting. Bismuth oxide is used as the attenuator. Particles with different properties are described. In one type, bismuth oxide is combined with active charcoal in an agarose matrix and serves as an absorbant for the free radioligand. In another type bismuth oxide is trapped within a polyacrylamide matrix to which antibodies are coupled. This particle can be used with a first- or a second-antibody bound activity. Application of the technique is illustrated with radioimmunoassays for thyroxin, triiodothyronine, human choriogonadotropin, and lutropin (luteinizing hormone).
Research Organization:
Univ. of Lund at Malmo General Hospital, Sweden
OSTI ID:
5799416
Journal Information:
Clin. Chem. (Winston-Salem, N.C.); (United States), Journal Name: Clin. Chem. (Winston-Salem, N.C.); (United States) Vol. 27:12; ISSN CLCHA
Country of Publication:
United States
Language:
English

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