Characterization of lanthanide ion binding to the EF-hand protein S100 beta by luminescence spectroscopy.
AuthorsChaudhuri D, Horrocks WD, Amburgey JC, Weber DJ
JournalBiochemistry
PubMed ID9245399
'S100 beta is a member of a group of low-molecular weight acidic calcium binding proteins widely distributed in the vertebrate nervous system containing two helix-loop-helix calcium binding motifs (sites I and II). In addition, S100 beta also has auxiliary Zn2+ binding sites that are distinct from the Ca2+ binding sites. ... More
Investigating the effects of posttranslational adenylylation on the metal binding sites of Escherichia coli glutamine synthetase using lanthanide luminescence spectroscopy.
AuthorsReynaldo LP, Villafranca JJ, Horrocks WD
JournalProtein Sci
PubMed ID8976562
'Lanthanide luminescence was used to examine the effects of posttranslational adenylylation on the metal binding sites of Escherichia coli glutamine synthetase (GS). These studies revealed the presence of two lanthanide ion binding sites of GS of either adenylylation extrema. Individual emission decay lifetimes were obtained in both H2O and D2O ... More
Cytotoxicity assays using cryopreserved target cells pre-labeled with the fluorescent marker europium.
AuthorsMaley DT, Simon P
JournalJ Immunol Methods
PubMed ID2230150
'We describe a method for standardizing cytotoxicity assays by the use of cryopreserved, fluorescently labeled target cells. The cells are labeled in batches with the fluorogenic element europium (Eu) and frozen in multiple aliquots. Replicate aliquots can be thawed on different days and used for cytotoxicity assays. Thawed pre-labeled cells ... More
Dual-label time-resolved fluoroimmunoassay for simultaneous detection of myoglobin and carbonic anhydrase III in serum.
AuthorsVuori J, Rasi S, Takala T, Väänänen K
JournalClin Chem
PubMed ID1764784
'We developed a dual-labeled time-resolved fluoroimmunoassay for simultaneous quantification of myoglobin (Mb) and carbonic anhydrase III (CA III) in serum involving polyclonal antibodies and the fluorescent lanthanides europium (Eu3+) and samarium (Sm3+). This solid-phase immunoassay is based on competition between Eu(3+)- or Sm(3+)-labeled antigen and the sample antigen for polyclonal ... More
Induction of antitumor immunity using bone marrow-generated dendritic cells.
AuthorsPorgador A, Snyder D, Gilboa E
JournalJ Immunol
PubMed ID8609412
'We have previously shown that bone marrow-generated dendritic cells (DC) pulsed with a class I-restricted peptide are potent inducers of CD8+ CTL. In the present study we have investigated whether bone marrow-generated DC are capable of inducing antitumor immunity. We show that a single immunization with DC pulsed with OVA ... More
Sensitive non-radioactive dot-blot hybridization using DNA probes labelled with chelate group substituted psoralen and quantitative detection by europium ion fluorescence.
AuthorsOser A, Roth WK, Valet G
JournalNucleic Acids Res
PubMed ID3344204
'A new labelling method for cloned DNA probes used in hybridization assays is described. The DNA insert of recombinant plasmid DNA was made partially single-stranded for the labelling reaction by a restriction enzyme digest, followed by a controlled exonuclease III incubation. A thiol-containing psoralen derivative was covalently bound through irradiation ... More
Europium as a label in time-resolved immunofluorometric assays.
AuthorsHemmilä I, Dakubu S, Mukkala VM, Siitari H, Lövgren T
JournalAnal Biochem
PubMed ID6375455
'A nonisotopic immunoassay has been developed based on a sensitive detection of europium (III) in water solution using time-resolved fluorometry. The europium label is bound to the antibody with EDTA derivatives, either diazophenyl-EDTA-Eu or isothiocyanatophenyl-EDTA-Eu. After the immunometric assay has been completed the europium is preferably dissociated from the antibody ... More
The development of non-separation time-resolved fluoroimmunoassays for the measurement of urinary metabolites.
AuthorsBarnard G, Kohen F, Mikola H, Lovgren T
JournalJ Biolumin Chemilumin
PubMed ID2801210
'We describe the principles of a new generation of sequential or simultaneous time-resolved fluoroimmunoassays, namely, simple, rapid, liquid-phase non-separation procedures which may be applied to the measurement of urinary steroid and drug metabolites. As an example, a method for the measurement of estrone-3-glucuronide in undiluted urine is reported. This method ... More
A fluorescence-based assay for quantitation of lymphokine-activated killer cell activity.
AuthorsVolgmann T, Klein-Struckmeier A, Mohr H
JournalJ Immunol Methods
PubMed ID2785144
'A fluorescence assay for the quantitation of tumor cell lysis by activated and non-activated killer (LAK) cells is described. The target cells are labelled with a europium chelate (Eu-diethylenetriaminopentaacetate) and after cytolysis caused by the LAK cells the Eu3+ complex is released into the culture supernatant. The addition of beta-naphthoyltrifluoroacetone ... More
Europium-labelled target cells in an assay of natural killer cell activity. I. A novel non-radioactive method based on time-resolved fluorescence.
AuthorsBlomberg K, Granberg C, Hemmilä I, Lövgren T
JournalJ Immunol Methods
PubMed ID3456003
'The use of a new marker for labelling cells used as targets for natural killer cells is described. The human erythroleukaemic cell line K-562 was used as target. The cells were labelled with europium diethylenetriaminopentaacetate (EuDTPA) chelates. The detection of the released marker is based on time-resolved fluorometry. The results ... More
The fluorometric determination of europium ion concentration as used in time-resolved fluoroimmunoassay.
AuthorsDakubu S, Ekins RP
JournalAnal Biochem
PubMed ID3920928
'A model of the relationships between optimal fluorescence yield, Eu3+ ion concentration, and the concentration of beta-diketone in the determination of Eu3+ ion concentration in aqueous solutions as used in time-resolved fluoroimmunoassays was developed. The model, in addition to optimizing the determination of the metal ion, also presents a new ... More
Confocal multilaser focusing and single-laser characterization of ultraviolet excitable stains of cellular preparations.
AuthorsKahn E, Frouin F, Souchier C, Bernengo JC, Bruzzoni-Giovanelli H, Clément O, Frija G, Di Paola R, Calvo F, Linares-Cruz G
JournalCytometry
PubMed ID10754516
'BACKGROUND: The aims of this study were (1) to realign cellular preparations when spots and structures are excited by different lasers of a confocal laser scanning microscope (multilaser studies); (2) to avoid the use of realigment methods by selecting fluorochromes that can be excited by only one laser (single-laser experiments). ... More
Europium-labelled target cells in an assay of natural killer cell activity. II. A novel non-radioactive method based on time-resolved fluorescence. significance and specificity of the method.
AuthorsBlomberg K, Granberg C, Hemmilä I, Lövgren T
JournalJ Immunol Methods
PubMed ID3745921
'The significance, specificity and high sensitivity of a new method to determine the natural killer cell cytolysis of europium diethylenetriaminepentaacetate (EuDTPA)-labelled target cells has been confirmed. The targets used in this release assay were the NK sensitive cell line K-562 and the resistant cell line Raji. The released EuDTPA was ... More
Time-resolved fluoroimmunoassay of human pancreatic phospholipase A2.
AuthorsEskola JU, Nevalainen TJ, Lövgren TN
JournalClin Chem
PubMed ID6193905
'We describe an immunofluorometric assay for human pancreatic phospholipase A2 based on time-resolved fluorescence. The labeled antibody technique in combination with the time-resolved 1-s fluorometric detection of the europium label, which essentially eliminates all background fluorescence, resulted in a high sensitivity (20 ng/L) and a wide (5000-fold) linear range. Nonspecific ... More
Europium(III) trisbipyridine cryptate label for time-resolved fluorescence detection of polymerase chain reaction products fixed on a solid support.
AuthorsLopez E, Chypre C, Alpha B, Mathis G
JournalClin Chem
PubMed ID8381731
'We report a method for the nonradioactive detection of specific amplified target DNA, based on a new long-lived fluorescent label, europium(III) trisbipyridine cryptate [TBP-(Eu3+)]. After a polymerase chain reaction with a set of nested primers, microtiter affinity-collected hybrids were recognized by a TBP(Eu3+)-labeled antibody. The particular structure of the label ... More
Europium chelate labels in time-resolved fluorescence immunoassays and DNA hybridization assays.
AuthorsDiamandis EP, Christopoulos TK
JournalAnal Chem
PubMed ID2270861
Improved detection by time-resolved fluorometry of specific DNA immobilized in microtiter wells with europium/metal-chelator labelled DNA probes.
AuthorsOser A, Valet G
JournalNucleic Acids Res
PubMed ID3419909
Encapsulation of europium in liposomes for use in an amplified immunoassay detection system.
AuthorsVonk GP, Wagner DB
JournalClin Chem
PubMed ID1893578
Time-resolved immunofluorometric detection of antigens separated by high-performance liquid chromatography and coated to polystyrene.
AuthorsDiamandis EP, Christopoulos TK
JournalBiotechniques
PubMed ID1716927
We use high-performance liquid chromatography with fraction collection to separate an antigen of interest. The antigen is then immobilized on polystyrene microtiter wells and detected with a specific antibody, followed by a second biotinylated antibody and streptavidin labeled with a fluorescent europium chelate. Fluorescence can be quantified with the use ... More
AuthorsGuo CY, Shankar RR, Abe S, Ye Z, Thomas RN, Kuo JE
JournalAnal Biochem
PubMed ID1481977
Synthesis of surface-functionalized, probe-containing latex nanospheres is described. Approximately 40,000 probe ions may be encapsulated in a nanosphere of 50 nm diameter. The probe may be a radionuclide or a lanthanide with long-lived fluorescence. Alternatively, a "cargo" of pharmaceutical interest may be used. The surface of each nanosphere contains thousands ... More
Competitive solid-phase immunoassay of testosterone using time-resolved fluorescence.
AuthorsBertoft E, Eskola JU, Näntö V, Lövgren T
JournalFEBS Lett
PubMed ID6745429
A competitive solid-phase immunoassay for the determination of testosterone in serum samples using time-resolved fluorescence is described. The solid phase is a testosterone-3-(O-carboxymethyl)-oxime-ovalbumin conjugate coated to polystyrene microtiter strips. Europium-labelled polyclonal and monoclonal antibodies against testosterone-3-(O-carboxymethyl)-oxime-bovine serum albumin were compared. Their behavior was quite similar although the polyclonal antibody was ... More
Time-resolved fluoroimmunoassay of pancreatic phospholipase A2.
AuthorsNevalainen TJ, Eskola JU
JournalKlin Wochenschr
PubMed ID2927048
We have developed an immunoassay for human pancreatic secretory phospholipase A2 based on time-resolved fluorescence. The labeled antibody technique in combination with the time-resolved fluorometric detection of the Europium label, which essentially eliminates all background fluorescence, resulted in a high sensitivity and a wide linear range. Our assay is a ... More
Determination of cytotoxic T lymphocyte activity by time-resolved fluorometry using europium-labelled concanavalin A-stimulated cells as targets.
AuthorsGranberg C, Blomberg K, Hemmilä I, Lövgren T
JournalJ Immunol Methods
PubMed ID2972782
Time-resolved fluorometry was used to detect the cytolysis of concanavalin A-stimulated blast cells by employing cells stimulated in a mixed lymphocyte culture as effectors. The target cells were labelled with europium diethylenetriaminopentaacetate (EuDTPA) chelates. The results obtained showed that this method, which has been successfully applied to the measurement of ... More
Two-site time-resolved immunofluorometric assay of human insulin.
AuthorsToivonen E, Hemmilä I, Marniemi J, Jørgensen PN, Zeuthen J, Lövgren T
JournalClin Chem
PubMed ID2420487
We describe a two-site "sandwich"-type time-resolved immunofluorometric assay for human insulin, based on use of two monoclonal antibodies with different specificities. The first antibody is immobilized on the surface of microtiter plate strip wells, the other is labeled with Eu3+. Serum samples can be assayed with one incubation step; two ... More
Fluorescence labelling with europium chelate of beta-diketones and application in time-resolved fluoroimmunoassays (TR-FIA).
AuthorsCi YX, Yang XD, Chang WB
JournalJ Immunol Methods
PubMed ID7876570
Five beta-diketone derivatives were studied for multiple labelling of proteins. The labelled proteins were characterized by absorption and fluorescence measurements. It was found that proteins labelled with chlorosulfonyl-thenoyltrifluoroacetone (CTTA) were able to form highly fluorescent complexes with Eu3+ which exhibited prolonged fluorescence whereas the Eu3+ complex of hydrolyzed CTTA exhibited ... More
A novel and sensitive method for the detection of secreted cell products using time-resolved fluorescence.
AuthorsRuedl C, Wick G, Wolf H
JournalJ Immunol Methods
PubMed ID8288896
A new test has been developed for the quantitative detection of products secreted from isolated cells, based on the use of lanthanide- rather than enzyme-linked streptavidin. Used as a label, europium (Eu3+) can be measured with high sensitivity by time-resolved fluorescence. The main advantages of this assay are both an ... More
Liposome immunoassay by long-lived fluorescence detection.
AuthorsOkabayashi Y, Ikeuchi I
JournalAnalyst
PubMed ID9764512
Immunoassay by fluorescence energy transfer from a europium chelate in liposome to allophycocyanin (APC) was demonstrated. Streptavidin or antibody to biotin was bonded to the liposome containing the europium chelate of 2-naphthoyltrifluoroacetone in the bilayer. When the biotin bonded to APC (APC-BT) was added to the prepared liposomes and the ... More
Time-resolved pulsed fluorescence immunometric assays of carcinoembryonic antigen.
AuthorsDakubu S, Hale R, Lu A, Quick J, Solas D, Weinberg J
JournalClin Chem
PubMed ID3052929
A time-resolved pulsed fluorescence immunometric assay (TR-PFIA) for carcinoembryonic antigen is described in which either Eu(III) or Tb(III) chelate is used as label. Described in detail is the assay involving the well-documented format of microtiter matrix and Eu(III) fluorescence enhanced with a beta-diketone and quantified in a commercial time-resolving fluorometer. ... More
Measurement of estrone-3-glucuronide in urine by rapid, homogeneous time-resolved fluoroimmunoassay.
AuthorsBarnard G, Kohen F, Mikola H, Lövgren T
JournalClin Chem
PubMed ID2702741
We describe a liquid-phase nonseparation time-resolved fluorescence immunoassay for measuring estrone-3-glucuronide in undiluted urine. The sensitivity, specificity, and accuracy are similar to those for a conventional separation fluoroimmunoassay or radioimmunoassay, but the speed, convenience, precision, reliability, and clinical utility of the new method are more advantageous. The labeled antigen, a ... More
Modified procedure for labelling target cells in a europium release assay of natural killer cell activity.
AuthorsPacifici R, Di Carlo S, Bacosi A, Altieri I, Pichini S, Zuccaro P
JournalJ Immunol Methods
PubMed ID8486925
Lanthanide europium chelated to diethylenetriaminopentaacetate (EuDTPA) can be used to label target cells such as tumor cells and lymphocytes (Blomberg et al., 1986a,b; Granberg et al., 1988). This procedure has permitted the development of new non-radioactive methods for the detection of target cell cytolysis by natural killer (NK) cells (Blomberg ... More
Fluorescent europium chelates as target cell markers in the assessment of natural killer cell cytotoxicity.
AuthorsBlomberg K, Ulfstedt AC
JournalJ Immunol Methods
PubMed ID8450237
A time-resolved fluorometric assay for the detection of natural killer cell activity against target cells labelled with the fluorescent chelate europium-6,6"-bis[N,N-bis(carboxymethyl)-aminomethyl]-4'-phenyl-2,2',6', 2"-terpyridine (EuCAPT) has been developed. In the assay released EuCAPT from lysed K-562 cells is measured in the supernatant after co-incubation of the target cells with effector cells. Thus, ... More
Detection of human immunodeficiency virus type 1 by using the polymerase chain reaction and a time-resolved fluorescence-based hybridization assay.
AuthorsDahlén PO, Iitiä AJ, Skagius G, Frostell A, Nunn MF, Kwiatkowski M
JournalJ Clin Microbiol
PubMed ID1890180
The polymerase chain reaction (PCR) has many potential applications in the field of nucleic acid diagnostics. In particular, it has been successfully applied to the detection of pathogens present in low copy numbers such as the human immunodeficiency virus type 1. Here we describe a time-resolved fluorescence-based hybridization assay which, ... More
Development of time-resolved immunofluorometric assay of vascular permeability factor.
AuthorsYeo KT, Sioussat TM, Faix JD, Senger DR, Yeo TK
JournalClin Chem
PubMed ID1733610
We describe a two-site time-resolved immunofluorometric assay for guinea pig vascular permeability factor (VPF) for quantifying VPF in different biological fluids. Antibody against the carboxy terminus (C-IgG) is immobilized on microtiter wells, and antibody against the amino terminus (N-IgG) is labeled with Eu(3+)-chelate. Line 10 tumor culture medium, known to ... More
An improved europium release assay for complement-mediated cytolysis.
AuthorsCui J, Bystryn JC
JournalJ Immunol Methods
PubMed ID1541836
An improved assay for complement-mediated cytolysis is described. The target cells are labeled with europium complexed to diethylenetriaminopentaacetate (Eu-DTPA). Cytolysis caused by antibody plus complement leads to the release of the Eu-DTPA complex which is then formed into a highly fluorescent chelate by the addition of 2-naphthoyltrifluoroacetone (2-NTA). The amount ... More
Theoretical limitations on immunoassay sensitivity. Current practice and potential advantages of fluorescent Eu3+ chelates as non-radioisotopic tracers.
AuthorsJackson TM, Ekins RP
JournalJ Immunol Methods
PubMed ID3512720
The sensitivity of any immunoassay is a complex function of the underlying physico-chemical basis of the technique and the size and source of 'experimental' errors. Analysis of this relationship emphasizes the distinction between competitive labelled analyte methods, e.g., RIA, and the non-competitive labelled antibody techniques, e.g., IRMA, implying that, in ... More
Rare earth cryptates and homogeneous fluoroimmunoassays with human sera.
AuthorsMathis G
JournalClin Chem
PubMed ID8375081
The rare earth cryptates are used as long-lived fluorescent labels. They are formed by inclusion of a europium ion in the intramolecular cavity of a macropolycyclic ligand containing bipyridine groups as light absorbers. The use of fluoride ions in the measuring medium allows a total shielding of the label fluorescence. ... More
Time-resolved fluorometric assay for leukocyte adhesion using a fluorescence enhancing ligand.
AuthorsSaarinen K, Kivistö K, Blomberg K, Punnonen K, Leino L
JournalJ Immunol Methods
PubMed ID10699576
A new 96-well microtiter plate, time-resolved fluorometric assay was developed to measure leukocyte adhesion in vitro. The assay is based on loading leukocytes with a fluorescence enhancing ligand 2,2':6', 2"-terpyridine-6,6"-dicarboxylic acid (TDA), which in its acetoxymethyl ester form readily diffuses through the cell membrane. After hydrolysis by nonspecific intracellular esterases, ... More
One-step all-in-one dry reagent immunoassays with fluorescent europium chelate label and time-resolved fluorometry.
AuthorsLövgren T, Meriö L, Mitrunen K, Mäkinen ML, Mäkelä M, Blomberg K, Palenius T, Pettersson K
JournalClin Chem
PubMed ID8697576
The availability of an intrinsically fluorescent, inert, and stable Eu chelate label made it feasible to design one-step all-in-one immunoassays with time-resolved fluorometry for detection. Both competitive and noncompetitive immunoassays are performed in microtitration wells containing all assay-specific components in a stable dry form. Only the sample and one assay ... More
Thiol-reactive luminescent chelates of terbium and europium.
AuthorsChen J, Selvin PR
JournalBioconjug Chem
PubMed ID10077482
Thiol-reactive lanthanide complexes have been synthesized that are luminescent when bound to terbium and/or europium. The complexes consist of a diethylenetriaminepentaacetate (DTPA) chelate covalently joined through one amide bond to a chromophore, carbostyril 124, and via a second amide bond to a maleimide, bromoacetamide, or pyridyldithio moiety. Site-specific attachment and ... More
A nonseparation, time-resolved fluoroimmunoassay to monitor ovarian function and predict potential fertility in women.
AuthorsBarnard G, O'Reilly C, Dennis K, Collins W
JournalFertil Steril
PubMed ID2744188
The authors describe a nonseparation, time-resolved fluoroimmunoassay involving the use of monoclonal antibodies for the measurement of estrone-3-glucuronide in urine. The method has appropriate sensitivity (12 nmol/l), better specificity than a conventional radioimmunoassay with polyclonal antibodies, and the advantages of speed, simplicity, less imprecision, and improved clinical effectiveness. The labeled ... More
Europium chelate-loaded liposomes: a tool for the study of binding and integrity of liposomes.
AuthorsOrellana A, Laukkanen ML, Keinänen K
JournalBiochim Biophys Acta
PubMed ID8865811
Using the biotin-streptavidin interaction as a model, we investigated the suitability of lanthanide chelates as encapsulated liposomal labels in liposome-based binding assays. Large unilamellar phospholipid:cholesterol liposomes containing europium-DTPA chelate and biotinylated phosphatidylethanolamine were prepared by detergent dialysis. The resulting Eu-liposomes ([symbol: see text] 120 nm) bound specifically to streptavidin in ... More
Simultaneous measurement of natural killer cell cytotoxicity against each of three different target cell lines.
AuthorsBlomberg K
JournalJ Immunol Methods
PubMed ID8308301
A time-resolved fluorometric assay for the simultaneous measurement of natural killer cell activity against three different lanthanide diethylenetriaminopentaacetate (LaDTPA) labelled target cell lines is described. The target cell line K-562 was labelled with SmDTPA, the cell line Molt with TbDTPA and the cell line Raji with EuDTPA. After co-incubation of ... More
Time-resolved immunofluorescence: a sensitive and specific assay for anti-HIV antibody detection in human sera.
AuthorsAceti A, Titti F, Verani P, Buttò S, Pennica A, Sebastiani A, Rossi GB
JournalJ Virol Methods
PubMed ID3312263
We describe a new immunoassay, time-resolved fluoroimmunoassay (TR-FIA), for detection of anti-HIV antibodies in human sera. This method is based on the use of a crude virus preparation coated on a polystyrene microtitre plate and of a swine anti-human IgG labelled with a rare earth metal, europium, as fluorescent label ... More
Elucidation of the metal-binding properties of the Klenow fragment of Escherichia coli polymerase I and bacteriophage T4 DNA polymerase by lanthanide(III) luminescence spectroscopy.
BACKGROUND: The exonuclease active site of the Klenow fragment (KF) of Escherichia coli DNA polymerase I has a double binding site for the two essential divalent metal ions in the presence of the nucleotide monophosphate dTMP. RESULTS: The luminescence spectroscopy observed upon binding of Eu3+ to the exonuclease active site ... More
Luminescence energy transfer using a terbium chelate: improvements on fluorescence energy transfer.
AuthorsSelvin PR, Hearst JE
JournalProc Natl Acad Sci U S A
PubMed ID7937831
We extend the technique of fluorescence resonance energy transfer (FRET) by introducing a luminescent terbium chelate as a donor and an organic dye, tetramethylrhodamine, as an acceptor. The results are consistent with a Förster theory of energy transfer, provided the appropriate parameters are used. The use of lanthanide donors, in ... More
Amine-reactive forms of a luminescent diethylenetriaminepentaacetic acid chelate of terbium and europium: attachment to DNA and energy transfer measurements.
AuthorsLi M, Selvin PR
JournalBioconjug Chem
PubMed ID9095352
An isothiocyanate form of a lanthanide chelate which is highly luminescent when bound to terbium or europium has been synthesized. The chelate consists of diethylenetriaminepentaacetic acid (DTPA) covalently joined to a chromophore, 7-amino-4-methyl-2(1H)-quinolinone (cs124), and to L-p-aminophenylalanine, in which the aromatic amine was further converted to an isothiocyanate group. Ethylenediamine ... More
Simultaneous quadruple-label fluorometric immunoassay of thyroid-stimulating hormone, 17 alpha-hydroxyprogesterone, immunoreactive trypsin, and creatine kinase MM isoenzyme in dried blood spots.
AuthorsXu YY, Pettersson K, Blomberg K, Hemmilä I, Mikola H, Lövgren T
JournalClin Chem
PubMed ID1394988
We describe a quadruple-label fluorometric immunoassay for simultaneously measuring four analytes: thyroid-stimulating hormone (TSH), 17 alpha-hydroxyprogesterone (17 alpha-OHP), immunoreactive trypsin (IRT), and creatine kinase MM (CK-MM). The assay is based on immunoreagents labeled with four different lanthanide ions (Eu3+, Tb3+, Sm3+, and Dy3+), on dissociative fluorescence enhancement applying the principle ... More
Time-resolved immunofluorometric assay for the ovarian carcinoma-associated antigenic determinant CA 125 in serum.
AuthorsBoerman OC, Thomas CM, Segers MF, Kenemans P, Lövgren T, Zurawski VR, Haisma HJ, Poels LG
JournalClin Chem
PubMed ID2446805
A time-resolved immunofluorometric assay (IFMA) is described for quantifying the ovarian carcinoma-associated antigenic determinant CA 125 in human serum. Monoclonal antibody to CA 125 is immobilized onto a microtiter well, and the same antibody labeled with a europium chelate is used as a tracer. After the immunoreaction the bound portion ... More
Determination of cytotoxic T-lymphocyte precursor frequencies using europium labeling as a nonradioactive alternative to labeling with chromium-51.
AuthorsBouma GJ, van der Meer-Prins PM, van Bree FP, van Rood JJ, Claas FH
JournalHum Immunol
PubMed ID1286979
We report on the use of europium (Eu) as a suitable nonradioactive alternative for target cell labeling in limiting dilution analysis (LDA) assays set up to determine cytotoxic T-lymphocyte precursor (CTLp) frequencies. A nonradioactive alternative to the commonly used chromium-51 (51Cr) release assay seems desirable because working with radioisotopes has ... More
A competitive dual-label time-resolved immunofluorometric assay for simultaneous detection of carbonic anhydrase I and II in cerebrospinal fluid.
AuthorsParkkila AK, Parkkila S, Serlo W, Reunanen M, Vierjoki T, Rajaniemi H
JournalClin Chim Acta
PubMed ID7850996
Carbonic anhydrase (CA) is functionally an important enzyme in the central nervous system (CNS) where it is involved in the control of acid-base balance and regulation of the production of cerebrospinal fluid (CSF). Isoenzyme II (CAII) is the most widely distributed CA in the CNS being specifically present in CNS ... More
Time-resolved delayed luminescence image microscopy using an europium ion chelate complex.
AuthorsMarriott G, Heidecker M, Diamandis EP, Yan-Marriott Y
JournalBiophys J
PubMed ID7811952
Improvements and extended applications of time-resolved delayed luminescence imaging microscopy (TR-DLIM) in cell biology are described. The emission properties of europium ion complexed to a fluorescent chelating group capable of labeling proteins are exploited to provide high contrast images of biotin labeled ligands through detection of the delayed emission. The ... More