Magnetic particle-based time-resolved fluoroimmunoassay for the simultaneous determination of α-fetoprotein and the free β-subunit of human chorionic gonadotropin

The Analyst ◽  
2013 ◽  
Vol 138 (13) ◽  
pp. 3697 ◽  
Author(s):  
Jing-Yuan Hou ◽  
Tian-Cai Liu ◽  
Zhi-Qi Ren ◽  
Mei-Jun Chen ◽  
Guan-Feng Lin ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Magnetic Particle ◽  
Β Subunit ◽  
Time Resolved

scholarly journals Simultaneous Determination of α-Fetoprotein and Free β-Human Chorionic Gonadotropin by Element-Tagged Immunoassay with Detection by Inductively Coupled Plasma Mass Spectrometry

2004 ◽  
Vol 50 (7) ◽  
pp. 1214-1221 ◽  
Author(s):  
Sichun Zhang ◽  
Chao Zhang ◽  
Zhi Xing ◽  
Xinrong Zhang
Keyword(s):  
Mass Spectrometry ◽  
Monoclonal Antibodies ◽  
Simultaneous Determination ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Inductively Coupled Plasma ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry

Abstract Background: An inductively coupled plasma mass spectrometry (ICP-MS)-based immunoassay has been proposed independently by Baranov et al. (Anal Chem 2002;74:1629–36) and our group, but the applicability of this method for multianalyte analysis in clinical samples has not been fully illustrated. We developed a dual-label immunoassay method for the simultaneous determination of α-fetoprotein (AFP) and free β-human chorionic gonadotropin (hCGβ) in human serum. Methods: Monoclonal antibodies immobilized on microtiter plates captured AFP and hCGβ, which were detected by use of Eu3+-labeled anti-AFP and Sm3+-labeled anti-hCGβ monoclonal antibodies. Eu3+ and Sm3+ were dissociated from the immunocomplex with HNO3 solution (10 mL/L) and delivered by peristaltic pump to the ICP mass spectrometer. Results: The measurable ranges of AFP and hCGβ were 4.6–500 and 5.0–170 μg/L, respectively, with detection limits of 1.2 and 1.7 μg/L (3 SD above mean of zero calibrator), respectively. The intraassay imprecision (CV) for AFP was 8.3%, 4.0%, and 2.7% at 16.3, 86, and 354 μg/L, respectively, and the interassay CV was 10%, 5.7%, and 3.5%. For hCGβ, the intraassay CV was 5.4%, 6.4%, and 3.1%, respectively, at 10.5, 45.2, and 105 μg/L, and the interassay CV was 7.2%, 8.0%, and 3.7%. Comparison with IRMAs for AFP and hCGβ yielded correlation coefficients (r2) of 0.97 and 0.95. Conclusions: Two proteins can be measured simultaneously by immunoassays using two rare earth elemental tags (Eu3+ and Sm3+) and ICP-MS detection. The multielement capability and the multiple potential elemental labels make ICP-MS attractive for multianalyte immunoassays. Implementation of ICP-MS-linked immunoassays may be relatively straightforward because the labeling and immunoreaction procedures have been well developed for clinical time-resolved immunofluorometric assays.

scholarly journals Free β-Subunit of Human Chorionic Gonadotropin in Serum Is a Diagnostically Sensitive Marker of Seminomatous Testicular Cancer

2008 ◽  
Vol 54 (11) ◽  
pp. 1840-1843 ◽  
Author(s):  
Anna Lempiäinen ◽  
Ulf-Håkan Stenman ◽  
Carl Blomqvist ◽  
Kristina Hotakainen
Keyword(s):  
Testicular Cancer ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Reference Intervals ◽  
Β Subunit ◽  
Serum Samples ◽  
Additional Information ◽  
Sensitive Marker

Abstract Background: We studied whether measurement of the free β subunit of human chorionic gonadotropin (hCGβ) in serum offers additional diagnostic information compared to determination of intact hCG alone in testicular cancer. Methods: We determined hCG and hCGβ with ultrasensitive assays in 94 serum samples obtained preoperatively, 22 samples obtained during relapse, and 3687 samples obtained during routine follow-up of 351 patients with testicular tumors. Results: In preoperative samples, isolated increases of hCGβ were seen in 40% of the samples from seminoma patients (n = 42) and in 8% of those from patients with nonseminomatous testicular cancer (NSGCT) (n = 51). Both markers were increased in 12% of the seminoma and 71% of the NSGCT patients and were within reference intervals in 43% of the seminoma and 20% of the NSGCT patients. Specific determination of hCGβ increased the frequency of marker-positive seminomas from 17% to 57% and of marker-positive relapses from 32% to 59% (n = 22). Theoretically, about 40% of marker-positive seminomas and relapses would have been missed with an assay measuring hCG and hCGβ together. Preoperative hCG and hCGβ concentrations correlated with stage, tumor histology, and disease-related mortality. Additionally, hCGβ correlated with tumor size. Conclusions: hCGβ is a diagnostically sensitive marker for testicular cancer. In patients with seminomatous testicular cancer, hCGβ is superior to hCG, and in some NSGCT patients it provides additional information.

ALPHALISA FOR THE DETERMINATION OF MEDIAN LEVELS OF THE FREE β SUBUNIT OF HUMAN CHORIONIC GONADOTROPIN IN THE SERUM OF PREGNANT WOMEN

2013 ◽  
Vol 34 (2) ◽  
pp. 134-148 ◽  
Author(s):  
Li-Ping Zou ◽  
Tian-Cai Liu ◽  
Guan-Feng Lin ◽  
Zhi-Ning Dong ◽  
Jing-Yuan Hou ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Β Subunit

scholarly journals Terbium and Rhodamine as Labels in a Homogeneous Time-resolved Fluorometric Energy Transfer Assay of the β Subunit of Human Chorionic Gonadotropin in Serum

1999 ◽  
Vol 45 (6) ◽  
pp. 855-861 ◽  
Author(s):  
Kaj Blomberg ◽  
Pertti Hurskainen ◽  
Ilkka Hemmilä
Keyword(s):  
Energy Transfer ◽  
Chorionic Gonadotropin ◽  
Decay Time ◽  
Human Chorionic Gonadotropin ◽  
Limit Of Detection ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Β Subunit ◽  
Time Resolved ◽  
Assay Format

Abstract Background: Fluorescence resonance energy transfer (FRET) is a powerful tool in analytical chemistry. The aim of the present work was to use FRET to design a homogeneous immunoassay. Methods: We used a highly fluorescent terbium (Tb3+) chelate (donor) and the organic fluorochrome rhodamine (acceptor) combined with time-resolved detection of the acceptor emission in homogeneous assay format for the measurement of the β subunit of human chorionic gonadotropin (βhCG) in serum. We used two antibodies labeled with Tb3+ and rhodamine, respectively, recognizing different epitopes on βhCG. The close proximity between the labels in the immunocomplex permitted energy transfer between the pulse-excited Tb3+ donor (decay time >1 ms) and the acceptor rhodamine (decay time of 3.0 ns). The prolonged emission of donor-excited acceptor (energy transfer) was measured after the short-lived background and acceptor emissions had decayed. The emission of donor-excited rhodamine was measured at a wavelength of where the emission of unbound donor is minimal. Results: The energy transfer signal was directly proportional to the βhCG concentration in the sample. The limit of detection was 0.43 μg/L, and the assay was linear up to 200 μg/L. Total assay imprecision in the range 10–185 μg/L was between 7.5% and 2.8%. Conclusions: Although less sensitive than heterogeneous, dissociation-enhanced europium-based separation assays, the presented assay format has advantages such as speed and simplicity, which make the assay format ideal for assays requiring a high throughput.

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