DE69415409T2 - Verfahren und Zusammensetzung zur Erzeugung verstärkter Chemilumineszenz von chemiluminszenten Verbindungen unter Verwendung dikationischer oberflächenaktiver Stoffe - Google Patents

Verfahren und Zusammensetzung zur Erzeugung verstärkter Chemilumineszenz von chemiluminszenten Verbindungen unter Verwendung dikationischer oberflächenaktiver Stoffe

Info

Publication number
DE69415409T2
DE69415409T2 DE69415409T DE69415409T DE69415409T2 DE 69415409 T2 DE69415409 T2 DE 69415409T2 DE 69415409 T DE69415409 T DE 69415409T DE 69415409 T DE69415409 T DE 69415409T DE 69415409 T2 DE69415409 T2 DE 69415409T2
Authority
DE
Germany
Prior art keywords
group
chemiluminescent compounds
composition
enhanced chemiluminescence
surfactants
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
DE69415409T
Other languages
English (en)
Other versions
DE69415409D1 (de
Inventor
Hasem Akhavan-Tafti
Zahra Arghavani
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Lumigen Inc
Original Assignee
Lumigen Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Lumigen Inc filed Critical Lumigen Inc
Publication of DE69415409D1 publication Critical patent/DE69415409D1/de
Application granted granted Critical
Publication of DE69415409T2 publication Critical patent/DE69415409T2/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
    • G01N33/5306—Improving reaction conditions, e.g. reduction of non-specific binding, promotion of specific binding
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C211/00—Compounds containing amino groups bound to a carbon skeleton
    • C07C211/62—Quaternary ammonium compounds
    • C07C211/63—Quaternary ammonium compounds having quaternised nitrogen atoms bound to acyclic carbon atoms
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
    • C07F9/00—Compounds containing elements of Groups 5 or 15 of the Periodic System
    • C07F9/02—Phosphorus compounds
    • C07F9/28—Phosphorus compounds with one or more P—C bonds
    • C07F9/54—Quaternary phosphonium compounds
    • C07F9/5449—Polyphosphonium compounds
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
    • C07F9/00—Compounds containing elements of Groups 5 or 15 of the Periodic System
    • C07F9/02—Phosphorus compounds
    • C07F9/28—Phosphorus compounds with one or more P—C bonds
    • C07F9/54—Quaternary phosphonium compounds
    • C07F9/5456—Arylalkanephosphonium compounds
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
    • C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
    • C12Q1/68—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving nucleic acids
    • C12Q1/6813—Hybridisation assays
    • C12Q1/6816—Hybridisation assays characterised by the detection means
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/52—Use of compounds or compositions for colorimetric, spectrophotometric or fluorometric investigation, e.g. use of reagent paper and including single- and multilayer analytical elements
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
    • G01N33/543—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals
    • G01N33/54393—Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/58—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving labelled substances
    • G01N33/582—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving labelled substances with fluorescent label

Landscapes

  • Health & Medical Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Immunology (AREA)
  • Molecular Biology (AREA)
  • Organic Chemistry (AREA)
  • Hematology (AREA)
  • Biomedical Technology (AREA)
  • Urology & Nephrology (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Microbiology (AREA)
  • Physics & Mathematics (AREA)
  • Analytical Chemistry (AREA)
  • Biotechnology (AREA)
  • Medicinal Chemistry (AREA)
  • Food Science & Technology (AREA)
  • Cell Biology (AREA)
  • General Physics & Mathematics (AREA)
  • Pathology (AREA)
  • Wood Science & Technology (AREA)
  • Proteomics, Peptides & Aminoacids (AREA)
  • Zoology (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Biophysics (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • General Engineering & Computer Science (AREA)
  • Genetics & Genomics (AREA)
  • Investigating Or Analysing Materials By The Use Of Chemical Reactions (AREA)
  • Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)
  • Luminescent Compositions (AREA)
  • Emulsifying, Dispersing, Foam-Producing Or Wetting Agents (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
DE69415409T 1993-06-24 1994-05-25 Verfahren und Zusammensetzung zur Erzeugung verstärkter Chemilumineszenz von chemiluminszenten Verbindungen unter Verwendung dikationischer oberflächenaktiver Stoffe Expired - Lifetime DE69415409T2 (de)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US08/082,091 US5451347A (en) 1993-06-24 1993-06-24 Methods and compositions providing enhanced chemiluminescence from chemiluminescent compounds using dicationic surfactants

Publications (2)

Publication Number Publication Date
DE69415409D1 DE69415409D1 (de) 1999-02-04
DE69415409T2 true DE69415409T2 (de) 1999-08-19

Family

ID=22169018

Family Applications (1)

Application Number Title Priority Date Filing Date
DE69415409T Expired - Lifetime DE69415409T2 (de) 1993-06-24 1994-05-25 Verfahren und Zusammensetzung zur Erzeugung verstärkter Chemilumineszenz von chemiluminszenten Verbindungen unter Verwendung dikationischer oberflächenaktiver Stoffe

Country Status (7)

Country Link
US (3) US5451347A (de)
EP (1) EP0630884B1 (de)
JP (2) JP2711073B2 (de)
AT (1) ATE174898T1 (de)
AU (1) AU663445B2 (de)
CA (1) CA2123753C (de)
DE (1) DE69415409T2 (de)

Families Citing this family (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4418349A1 (de) * 1994-05-26 1995-11-30 Hoechst Ag Bisquartäre Ammoniumverbindungen des 2,2'-Dimethyl-1,1'-binaphthyls und Verfahren zu deren Herstellung
US5773628A (en) * 1994-11-14 1998-06-30 Tropix, Inc. 1,2-dioxetane compounds with haloalkoxy groups, methods preparation and use
US5853974A (en) * 1995-06-07 1998-12-29 Chiron Corporation Enhancement of alkaline phosphatase with SDS in chemiluminescent substrates
US5777135A (en) * 1995-07-31 1998-07-07 Lumigen, Inc. Di-substituted 1,2-dioxetane compounds having increased water solubility and assay compositions
US5721370A (en) * 1995-07-31 1998-02-24 Lumigen Inc. Water soluble tri-substituted 1,2-dioxetane compounds and assay compositions having increased storage stability
US5631167A (en) * 1995-07-31 1997-05-20 Bayer Corporation Capsule chemistry analytical methods employing dioxetane chemiluminescence
US6247995B1 (en) 1996-02-06 2001-06-19 Bruce Bryan Bioluminescent novelty items
US5876995A (en) * 1996-02-06 1999-03-02 Bryan; Bruce Bioluminescent novelty items
US5772926A (en) * 1997-05-13 1998-06-30 Lumigen, Inc. Chemiluminescent reactions using dihydroxyaromatic compounds and heterocyclic enol phosphates
US5840963A (en) * 1997-05-13 1998-11-24 Lumigen, Inc. Chemiluminescent reactions using dihydroxyaromatic compounds and heterocyclic enol phosphates
AU8224998A (en) * 1997-07-04 1999-01-25 Nycomed Amersham Plc Peroxidase-catalysed fluorescence
US6284194B1 (en) 1998-03-11 2001-09-04 Albert E. Chu Analytical assay device and methods using surfactant treated membranes to increase assay sensitivity
US6232107B1 (en) 1998-03-27 2001-05-15 Bruce J. Bryan Luciferases, fluorescent proteins, nucleic acids encoding the luciferases and fluorescent proteins and the use thereof in diagnostics, high throughput screening and novelty items
US6068979A (en) * 1998-04-22 2000-05-30 Lumigen, Inc. Simplified sequential chemiluminescent detection
CA2371625C (en) * 1999-04-30 2012-04-17 Slil Biomedical Corporation Polyamines and their use in therapy
WO2000066175A2 (en) 1999-04-30 2000-11-09 Slil Biomedical Corporation Conjugates as therapies for cancer and prostate diseases
US6783948B1 (en) * 1999-07-30 2004-08-31 Bayer Corporation Chemiluminescent acridinium compounds and analogues thereof as substrates of hydrolytic enzymes
US7028687B1 (en) 1999-08-26 2006-04-18 Precious Life, Llc Escape hood
WO2002091989A2 (en) * 2000-11-08 2002-11-21 Slil Biomedical Corporation Antiviral therapies using polyamine or polyamine analog-amino acid conjugates
EP1436246A1 (de) * 2001-10-16 2004-07-14 SLIL Biomedical Corporation Oligoamin-verbindungen und ihre derivate für die krebstherapie
WO2003099802A1 (en) * 2002-05-23 2003-12-04 Brij Pal Giri POLYMERIC AMMONIUM AND OR PHOSPHONIUM SALTS HAVING ADDED π-ELECTRONS AND HIGHER MOLECULAR WEIGHT AS ENHANCERS FOR CHEMILUMINESCENT SYSTEMS
US20040259182A1 (en) * 2003-06-17 2004-12-23 Brooks Edwards Arrays for chemiluminescent assays, methods of making the arrays and methods of detecting chemiluminescent emissions on solid supports
US20050019778A1 (en) * 2003-07-17 2005-01-27 Voyta John C. Sequential generation of multiple chemiluminescent signals on solid supports
US20050026151A1 (en) * 2003-07-17 2005-02-03 Voyta John C. Simultaneous generation of multiple chemiluminescent signals on solid supports
WO2005047230A1 (en) * 2003-11-13 2005-05-26 The University Of Sydney Bis-cationic compounds and use thereof
US8168830B2 (en) * 2004-07-23 2012-05-01 Sigma-Aldrich Co. Llc High stability diionic liquid salts
US20060234251A1 (en) * 2005-04-19 2006-10-19 Lumigen, Inc. Methods of enhancing isolation of RNA from biological samples
WO2008095069A2 (en) * 2007-01-31 2008-08-07 Sigma-Aldrich Co. High stability polyionic liquid salts
CN101784897A (zh) * 2007-05-23 2010-07-21 应用生物系统有限公司 通过从活化的化学发光的基质将能量转移至能量受体染料来检测生物分子的试剂、试剂盒和方法
CN102311730B (zh) 2010-06-30 2014-09-24 深圳迈瑞生物医疗电子股份有限公司 化学发光液,增强化学发光的试剂和方法
CN102311731B (zh) 2010-06-30 2016-08-03 深圳迈瑞生物医疗电子股份有限公司 增强化学发光的试剂、方法和化学发光液
CN102329611B (zh) 2010-07-13 2015-01-07 深圳迈瑞生物医疗电子股份有限公司 化学发光增强试剂及其使用方法和化学发光液
CN110095453A (zh) * 2018-01-30 2019-08-06 南京理工大学 季鏻盐化合物、制备方法及其在电致化学发光生物检测中的应用
WO2024026467A1 (en) 2022-07-29 2024-02-01 Beckman Coulter, Inc. Chemiluminescent reagents for detection of alkaline phosphatases

Family Cites Families (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3079436A (en) * 1955-11-25 1963-02-26 Rohm & Haas Bis-quaternary ammonium compounds
US3071618A (en) * 1956-02-02 1963-01-01 Pfizer & Co C Diquaternary ammonium salts of n, n, n', n'-tetra substituted alkylene diamines
US3330868A (en) * 1963-10-14 1967-07-11 Monsanto Res Corp Method of making phosphonium methylene phosphoranes
US3322861A (en) * 1964-06-12 1967-05-30 American Cyanamid Co Vinyl resins containing diphosphonium halides as flame-retardants
US3341605A (en) * 1964-11-13 1967-09-12 Monsanto Res Corp Preparation of methylene bis(trihydrocarbylphosphonium) tetrahalides
US3349032A (en) * 1965-01-04 1967-10-24 Petrolite Corp Method of preventing the swelling of clays in subterranean formations
US3936503A (en) * 1965-10-22 1976-02-03 Akzona Incorporated Aryl-substituted aliphatic diquaternary compounds
US3422048A (en) 1966-01-19 1969-01-14 American Cyanamid Co Flame retardant compositions for plastics
US3417003A (en) 1966-02-21 1968-12-17 Sprague Electric Co Polymer deposit electrochemically
US4166073A (en) * 1968-03-27 1979-08-28 Colgate Palmolive Company Unsymmetrical oligoquaternary ammonium compounds
US3925556A (en) * 1971-09-30 1975-12-09 Colgate Palmolive Co Anti microbial compositions containing unsymmetrical oligoquaternary ammonium compounds
US4102876A (en) 1977-04-18 1978-07-25 Exxon Research & Engineering Co. Quaternary phosphonium ionomers
JPS5851850B2 (ja) * 1978-03-24 1983-11-18 株式会社日立製作所 固形物水力輸送装置
JPS5932585B2 (ja) * 1978-12-05 1984-08-09 花王株式会社 繊維用柔軟剤
AU558939B2 (en) * 1982-03-03 1987-02-12 British Technology Group Limited Enhanced luminescent and luminometric assay
GB8420053D0 (en) * 1984-08-07 1984-09-12 Secr Social Service Brit Enhanced luminescent/luminometric assay
US5004565A (en) * 1986-07-17 1991-04-02 The Board Of Governors Of Wayne State University Method and compositions providing enhanced chemiluminescence from 1,2-dioxetanes
US4959182A (en) * 1986-07-17 1990-09-25 Board Of Governors Of Wayne State University Method and compositions providing enhanced chemiluminescence from 1,2-dioxetanes
US4931223A (en) * 1986-07-24 1990-06-05 Tropix, Inc. Methods of using chemiluminescent 1,2-dioxetanes
US4978614A (en) * 1988-10-26 1990-12-18 Tropix, Inc. Method of detecting a substance using enzymatically-induced decomposition of dioxetanes
US4927769A (en) * 1987-07-08 1990-05-22 Ciba Corning Diagnostics Corp. Method for enhancement of chemiluminescence
US4952707A (en) * 1988-06-30 1990-08-28 Tropix, Inc. Enzymatically-cleavable chemiluminescent fused polycyclic ring-containing 1,2-dioxetanes
US5298197A (en) * 1988-10-06 1994-03-29 The United States Of America As Represented By The Secretary Of The Navy Chemiluminescent microemulsions
US5032381A (en) * 1988-12-20 1991-07-16 Tropix, Inc. Chemiluminescence-based static and flow cytometry
BE1002830A5 (fr) * 1989-02-15 1991-06-25 Fabricom Air Conditioning Sa Composition desinfectante et/ou de conservation et procede de desinfection et/ou de conservation d'aliments.
GB2233451B (en) 1989-06-27 1993-09-15 Tropix Inc Chemiluminescence enhancement
BE1003510A5 (fr) * 1989-10-09 1992-04-07 Fabricom Air Conditioning Sa Composition desinfectante et procede de desinfection.
JPH0579985A (ja) * 1991-09-24 1993-03-30 Kyoto Daiichi Kagaku:Kk 化学発光増強剤及び増強方法
US5242684A (en) * 1991-10-25 1993-09-07 Isp Investments Inc. Antimicrobial, low toxicity, non-irritating composition comprising a blend of bis-quaternary ammonium compounds coprecipitated with a copolymer of vinylpyrrolidone and an acrylamido or vinyl quaternary ammonium monomer
US5393469A (en) * 1992-03-20 1995-02-28 Lumigen, Inc. Polymeric phosphonium salts providing enhanced chemiluminescence from 1,2-dioxetanes
US5279940A (en) * 1992-08-03 1994-01-18 Eastman Kodak Company Chemiluminescent composition containing cationic surfactants or polymers and 4'-hydroxyacetanilide, test kits and their use in analytical methods

Also Published As

Publication number Publication date
JPH1081875A (ja) 1998-03-31
EP0630884B1 (de) 1998-12-23
DE69415409D1 (de) 1999-02-04
JP2989785B2 (ja) 1999-12-13
AU663445B2 (en) 1995-10-05
ATE174898T1 (de) 1999-01-15
AU6318794A (en) 1995-01-05
EP0630884A2 (de) 1994-12-28
CA2123753C (en) 1997-08-26
JP2711073B2 (ja) 1998-02-10
US5650099A (en) 1997-07-22
CA2123753A1 (en) 1994-12-25
EP0630884A3 (en) 1995-01-18
US5484556A (en) 1996-01-16
US5451347A (en) 1995-09-19
JPH0789908A (ja) 1995-04-04

Similar Documents

Publication Publication Date Title
DE69415409T2 (de) Verfahren und Zusammensetzung zur Erzeugung verstärkter Chemilumineszenz von chemiluminszenten Verbindungen unter Verwendung dikationischer oberflächenaktiver Stoffe
DE3851502T2 (de) Fluoreszierende Indikator-Farbstoffe für Kalzium, die bei langen Wellenlängen arbeiten.
MX165512B (es) Aditivo de carbamato para composicion lubricante
DE3476676D1 (en) Polishing composition based on cerium and process for making it
MX172244B (es) Revestimientos contra contaminantes
ES2177248T3 (es) Poliamida inherentemente foto- y termo-estabilizada y procedimiento para su preparacion.
EP0228148A3 (de) Polyorgano(hydro)silazane und ihr Herstellungsverfahren
MX165509B (es) Un multisilano que contiene anillo de triazina y metodo para prepararlo
ATE325T1 (de) Verfahren zum anlagern von si-h-verbindungen an aliphatische mehrfachbindung.
HUT60136A (en) Process for producing amino glycoside compositions with reduced nephrotoxicity
DE69026851T2 (de) Verfahren zur Erhöhung von Chemilumineszenz
ATE125573T1 (de) Verfahren zur bestimmung einer substanz durch verwendung von chemilumineszenz.
DE69001732D1 (de) Verfahren zur enantioselektiven herstellung von phenylisoserin-derivaten.
ES8704470A1 (es) Procedimiento para la determinacion optica de la lipasa
PT79172B (de) Verfahren zur herstellung von nukleasidalkyl-aralkyl- und -aryl-phosphoniten und phosphonaten
DE3483672D1 (de) Verfahren zur herstellung von siliciumcarbid.
CA2068317A1 (en) Process for obtaining bis (2,4-di-tert-butylphenyl) halophosphites
DE3861862D1 (de) Verfahren zur herstellung von oximosilanen.
DE59202415D1 (de) Verfahren zur herstellung von 5,6-dihydroxyindolinen.
DE3584623D1 (de) Zusammensetzung und verfahren zur konditionierung der oberflaeche von kunststoffsubstraten vor der metallplattierung.
ATE127159T1 (de) Verfahren zur racemattrennung von 4-aryl-2-oxo- pyrrolidin-3-carbonsäure-estern.
TJ280B (en) Method of producing substantially free of dust fines and method of soil disinfection
AT387214B (de) Verfahren zur herstellung neuer n-substituierter, estergruppen enthaltender acrylamide
BR0016502A (pt) Composição polimerizável e artigo polimerizado
ATE135037T1 (de) Verfahren zum erhöhen des bleicheffektes beim waschen und verwendung bestimmter amphoterer verbindungen in einer waschmittelzusammensetzung zum erhöhen des bleicheffektes

Legal Events

Date Code Title Description
8364 No opposition during term of opposition