In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 97, No. 6 ( 2000-03-14), p. 2445-2449
Abstract:
The practice of immunoassay has experienced a widespread transition
from radioisotopic labeling to nonisotopic labeling over the last two decades. Radioisotope labels have drawbacks that hamper their
applications: ( i ) perceived radiation hazards of
reagents, ( ii ) regulatory requirements and disposal
problems of working with radioactive materials, and ( iii ) short shelf-life of the labeled
reagents. The advantage of isotopic labeling is the incorporation into analytes without altering structure or reactivity, as is often the case
with ELISA or fluorescent detection systems. We developed a format for isotope label immunoassay with the long-life isotope 14 C as
the label and accelerator mass spectrometer (AMS) as the detection system. AMS quantifies attomole levels of several isotopes, including 14 C. With this exquisite sensitivity, the sensitivity of an
immunoassay is limited by the K d of the
antibody and not the detection system. The detection limit of the assays for atrazine and
2,3,7,8-tetrachlorodibenzo- p -dioxin was 2.0 ×
10 −10 M and 2.0 × 10 −11 M,
respectively, approximately an order of magnitude below the standard enzyme immunoassay. Notably, 〈 1 dpm (0.45 pCi) of 14 C-labeled compound was used in each assay, which is well
below the limit of disposal (50 nCi per g) as nonradioactive waste. Thus, endogenous reporter ligands quantified by AMS provide
the advantages of an RIA without the associated problems of radioactive waste.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.040575997
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2000
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
