WO1989001047A1 - Enzymatic assay - Google Patents
Enzymatic assay Download PDFInfo
- Publication number
- WO1989001047A1 WO1989001047A1 PCT/GB1988/000641 GB8800641W WO8901047A1 WO 1989001047 A1 WO1989001047 A1 WO 1989001047A1 GB 8800641 W GB8800641 W GB 8800641W WO 8901047 A1 WO8901047 A1 WO 8901047A1
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- WO
- WIPO (PCT)
- Prior art keywords
- assay
- choline
- bed
- enzyme
- immobilised
- Prior art date
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Classifications
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- 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
- C12Q1/34—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving hydrolase
- C12Q1/44—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving hydrolase involving esterase
- C12Q1/46—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving hydrolase involving esterase involving cholinesterase
-
- 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
- C12Q1/001—Enzyme electrodes
- C12Q1/004—Enzyme electrodes mediator-assisted
Definitions
- This invention relates to an enzyme catalysed assay, particularly using peroxidases.
- the assay is particularly suitable for the assay of choline and acetylcholine.
- Acetylcholine is converted by the enzyme action of acetylcholinesterase to choline which is further converted under the action of choline oxidase to betaine with formation hydrogen peroxide which may then be determined electrochemically. It is this system which forms the basis of known assays for choline and acetylcholine.
- the assay described may be be coupled to a separation step using HPLC to separate the choline and acetylcholine so that they may be assayed separately.
- An object of the present invention is to provide an improved enzymatic assay.
- an enzymatic assay comprising contacting a solution of an analyte in a solution of a redox reaction mediator with a bed of immobilised enzyme which includes at least a peroxidase and electrochemically determining the concentration of the analyte by monitoring of the redox reaction.
- the redox reaction mediator is a metal dicyclopentadienyl monocarboxylic acid, most preferably ferrocene monocarboxylic acid.
- the redox reaction is monitored by means of a wall jet electrode.
- the immobilised enzyme may be choline esterase and the peroxidase may be horseradish peroxidase.
- the enzyme bed may additionally include acetylcholinesterase.
- the enzyme bed may contain glucose oxidase and horseradish peroxidase.
- the enzymatic assay is utilised as a detector of the eluate from a chromatographic column wherein components amenable to detection by the assay are preseparated.
- the present invention therefore, provides a method for the assaying of choline and acetylcholine, comprising separating the choline and acetylcholine chromatographically using an eluant containing, in solution, a redox mediator, delivering the eluate continuously to a bed of immobilised enzyme containing choline oxidase, acetylcholinesterase and horseradish peroxidase, and delivering the effluent stream from the enzyme bed to a wall jet electrode for electrochemical determination of the components.
- the choline oxidase and the acetylcholinesterase may be immobilised on aminopropyl-activated glass beads and the horseradish peroxidase on Sepharose (Trade
- the immobilised enzymes be in the form of alternating layers of glass and Sepharose in the bed.
- a suitable stationary phase is Hypersil 5A (Trade Mark) reverse phase and the mobi le phase may be an aqueous solution of 20mM phosphate buf fer , 5mM tetramethylammonium chloride at pH 7. 5 which also contains , as redox mediator, 2mM of ferrocene monocarboxylic acid, the solution having been filtered through a 0 . 6 micrometer filter .
- the choline oxidase and acetylcholinesterase may be co-immobilised on glass beads as follows : lg of aminopropyl-activated glass beads were placed in 10ml of
- the electrode reaction is:
- apparatus for conducting an enzymatic assay comprising in serial connection for throughflow of liquid an HPLC column a packed enzyme bed and a wall jet electrode.
- Fig.l is a schematic flow diagram of appartus of the invention.
- Fig.2 is a detail of the packed enzyme bed
- Fig.3 is a detail of the wall jet electrode
- Fig.4 shows the equations of the reactions involved in the assay
- Fig. 5 shows a typical result using the assay of this invention on rat brain dialysate.
- a reservior 1 for mobile phase which contains ferrocene monocarboxylic acid as a redox mediator, is connected by tubing to a pump 2 and thence to a HPLC column 3, a sample introduction port 4 being provided between the pump and the column.
- the column 3 is connected to a packed enzyme bed 5 and thence t ⁇ the inlet of a wall jet electrode 6, the outlet of which runs to drain.
- the enzyme bed 5 consists of a tube 10, having and inlet end fitting 11, provided with a gauze 12 of stainless steel secured between the tube 10 and the end fitting 11, and an outlet end fitting 13 having a stainless. steel gauze 14 and a sintered glass plate 15 secured between the outlet end fitting 12.
- the wall jet electrode 6, as shown in Fig.3, has a body 20 and four inwardly directed electrode components, an inlet port 21 for connection to the outlet end fitting of the 13 (Fig.2) of the enzyme bed 5 (Fig.2) and a glassy carbon disc electrode 14 disposed on the opposite side of the body 20 so as to receive a jet of liquid from the inlet port 21.
- the remaining two components are a platinum tube counter electrode 22 and a silver/silver chloride reference electrode 23.
- the disc electrode 14 may be of the disc/ring configuration but, for the purpose of this invention, the platinum ring is not used.
- the wall jet electrode is maintained at a voltage of -27mV which obviates interference from other neurotransmitters such as catecholamine which may be present in an assay sample derived from neuronal fluid.
- R diameter of disc (0.16cm);
- V f flow rate
- the present invention is applicable to the assaying of biochemicals which when acted upon by a suitably selected enzyme result in the formation of hydrogen peroxide.
- the hydrogen peroxide then oxidises the ferrocene to ferricinium carboxylic acid which reaction may be assayed by the wall jet electrode.
- the sources of the samples for assay would, typically, be biological fluids which, if circumstances call for it, may be pretreated by, for example, dialysis, filtration, ultrafiltration or like processes, to remove interfering or contaminating materials.
- Brain fluid may be predialysed to remove interfering material to provide a sample for assay by the process of the invention.
- catecholamine which is also present in samples of neuronal fluid, is not detected by the assay of this invention.
- Fig.5 shows the type of output obtained from the wall jet electrode acting upon the eluate from a chromatographic column, the sample being rat brain dialysate.
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Zoology (AREA)
- Wood Science & Technology (AREA)
- Proteomics, Peptides & Aminoacids (AREA)
- Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- Microbiology (AREA)
- Immunology (AREA)
- Physics & Mathematics (AREA)
- Molecular Biology (AREA)
- Biotechnology (AREA)
- Biophysics (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- Bioinformatics & Cheminformatics (AREA)
- General Engineering & Computer Science (AREA)
- General Health & Medical Sciences (AREA)
- Genetics & Genomics (AREA)
- Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)
Abstract
An enzymatic assay comprises contacting a solution of an analyte, which may be the eluate from a chromatographic separation column, in a solution of a redox reaction mediator with a bed of immobilised enzyme which includes at least a peroxidase and electrochemically determining the concentration of the analyte by monitoring of the redox reaction. The assay is particularly suitable for the co-determination of choline and acetylcholine using the enzymes choline oxidase and acetylcholine esterase, immobilised on glass beads, and horseradish peroxidase, immobilised on Sepharose (Trade Mark). Glucose may be determined using glucose oxidase and horseradish peroxidase. The electrochemical monitoring is best carried out using a wall jet electrode.
Description
ENZYMATIC ASSAY
This invention relates to an enzyme catalysed assay, particularly using peroxidases. The assay is particularly suitable for the assay of choline and acetylcholine.
Acetylcholine is converted by the enzyme action of acetylcholinesterase to choline which is further converted under the action of choline oxidase to betaine with formation hydrogen peroxide which may then be determined electrochemically. It is this system which forms the basis of known assays for choline and acetylcholine. The assay described may be be coupled to a separation step using HPLC to separate the choline and acetylcholine so that they may be assayed separately.
An object of the present invention is to provide an improved enzymatic assay.
According to the present invention there is provided an enzymatic assay comprising contacting a solution of an analyte in a solution of a redox reaction mediator with a bed of immobilised enzyme which includes at least a peroxidase and electrochemically determining the concentration of the analyte by monitoring of the redox reaction.
Preferably the redox reaction mediator is a metal dicyclopentadienyl monocarboxylic acid, most preferably ferrocene monocarboxylic acid.
It is further preferred that the redox reaction is monitored by means of a wall jet electrode.
In a method for the determination of choline, the immobilised enzyme may be choline esterase and the peroxidase may be horseradish peroxidase. For the co-determination of acetylcholine, the enzyme bed may additionally include acetylcholinesterase. For the determination of glucose, the enzyme bed may contain glucose oxidase and horseradish peroxidase.
In a preferred embodiment of the invention, the enzymatic assay is utilised as a detector of the eluate from a chromatographic column wherein components amenable to detection by the assay are preseparated.
The present invention, therefore, provides a method for the assaying of choline and acetylcholine, comprising separating the choline and acetylcholine chromatographically using an eluant containing, in solution, a redox mediator, delivering the eluate continuously to a bed of immobilised enzyme containing choline oxidase, acetylcholinesterase and horseradish peroxidase, and delivering the effluent stream from the enzyme bed to a wall jet electrode for electrochemical determination of the components.
The choline oxidase and the acetylcholinesterase may be immobilised on aminopropyl-activated glass beads and the horseradish peroxidase on Sepharose (Trade
Mark) . It is preferred that the immobilised enzymes be in the form of alternating layers of glass and Sepharose in the bed.
For the chromatographic separation, a suitable stationary phase is Hypersil 5A (Trade Mark) reverse phase and the mobi le phase may be an aqueous solution of 20mM phosphate buf fer , 5mM tetramethylammonium chloride at pH 7. 5 which also contains , as redox mediator, 2mM of ferrocene monocarboxylic acid, the solution having been filtered through a 0 . 6 micrometer filter .
The choline oxidase and acetylcholinesterase may be co-immobilised on glass beads as follows : lg of aminopropyl-activated glass beads were placed in 10ml of
0 . 1M phosphate at pH4 and exhaustively degassed to remove all air from the pores ; 38mg of f reshly prepared l-cyclohexyl-3- ( 2-morpholinethyl) -carbodiimide metho-p_-toluene sulphonate were added and dissolved; then O . lmg of acetylcholinesterase in 1ml of water was added followed by 90mg of choline oxidase in 5ml of water , the choline oxidase dissolved s lowly to prevent self precipitation; the mixture, then being rotated overnight and washed with one litre of 0 .5M sodium chloride and one litre of water over a sintered glass filter .
The reactions invo lved in the assay of the invention are as follows :
acetylcholinesterase Acetylcholine + H-0 _\~> Choline + Acetate
choline oxidase Choline + 20 ~^~~ Betaine + 2H20
horseradish peroxidase 2H 0 + 4FcC00H ; ^~ 4Fc+C00H + 4H20
The choline reaction actually occurs in two steps:
choline oxidase Choline + Ct ^"-Betaine aldehyde + ILO
choline oxidase Betaine aldehyde + (1 _5»-Betaine + H n
The electrode reaction is:
4Fc+C00H + 4e -^~~ 4FcC00H
[Acetylcholinesterase ex Electrophorous electricus (E.C. 3.1.1.7)
Choline oxidase ex Arthobacter globiformis (E.C. 1.1.3.17) Horseradish peroxidase ex Horseradish (E.C. 1.11.1.7) Fc = ferrocene: Fc = ferricinium]
According to the present invention there is also provided apparatus for conducting an enzymatic assay comprising in serial connection for throughflow of liquid an HPLC column a packed enzyme bed and a wall jet electrode.
The invention is illustrated by the accompanying drawings of which:
Fig.l is a schematic flow diagram of appartus of the invention;
Fig.2 is a detail of the packed enzyme bed; Fig.3 is a detail of the wall jet electrode; Fig.4 shows the equations of the reactions involved in the assay; and, Fig. 5 shows a typical result using the assay of this invention on rat brain dialysate.
Referring to Fig.l, a reservior 1 for mobile phase, which contains ferrocene monocarboxylic acid as a redox mediator, is connected by tubing to a pump 2 and thence to a HPLC column 3, a sample introduction port 4 being provided between the pump and the column. The column 3 is connected to a packed enzyme bed 5 and thence tσ the inlet of a wall jet electrode 6, the outlet of which runs to drain.
As shown in Fig.2, the enzyme bed 5 consists of a tube 10, having and inlet end fitting 11, provided with a gauze 12 of stainless steel secured between the tube 10 and the end fitting 11, and an outlet end fitting 13 having a stainless. steel gauze 14 and a sintered glass plate 15 secured between the outlet end fitting 12.
The wall jet electrode 6, as shown in Fig.3, has a body 20 and four inwardly directed electrode components, an inlet port 21 for connection to the outlet end fitting of the 13 (Fig.2) of the enzyme bed 5 (Fig.2) and a glassy carbon disc electrode 14 disposed on the opposite side of the body 20 so as to receive a jet of liquid from the inlet port 21. The remaining two components are a platinum tube counter electrode 22 and a silver/silver chloride reference electrode 23. As shown in the enlarged detail in Fig.3, the disc electrode 14 may be of the disc/ring configuration but, for the purpose of this invention, the platinum ring is not used.
In use for the determination of choline/ acetylcholine, the wall jet electrode is maintained at a voltage of -27mV which obviates interference from other neurotransmitters such as catecholamine which may be present in an assay sample derived from neuronal fluid.
SUBSTITUTESHEET
The limiting diffusion current of the electrode is given by the equation: id = 1.38nFD2 3u-5/12R3 a-1/2v3/4C in which; ifl = diffusion current; n = number of electrons; F = Faraday constant; u = kinematic viscosity;
D =diffusion coefficient (determined by rotation step to be 7.6 x 10 —6'* a = diameter of jet (0.05cm);
R = diameter of disc (0.16cm);
Vf = flow rate; and,
C = concentration of analyte.
The present invention is applicable to the assaying of biochemicals which when acted upon by a suitably selected enzyme result in the formation of hydrogen peroxide. The hydrogen peroxide then oxidises the ferrocene to ferricinium carboxylic acid which reaction may be assayed by the wall jet electrode. The sources of the samples for assay would, typically, be biological fluids which, if circumstances call for it, may be pretreated by, for example, dialysis, filtration, ultrafiltration or like processes, to remove interfering or contaminating materials.
Of particular interest is the assay of neuronal fluid for the neurotransmitter acetylcholine and its precursor/metabolite choline. Brain fluid may be predialysed to remove interfering material to provide a sample for assay by the process of the invention. As has been mentioned above, catecholamine which is also present in samples of neuronal fluid, is not detected by the assay of this invention. Fig.5 shows the type of output obtained from the wall jet electrode acting upon the eluate from a chromatographic column, the sample being rat brain dialysate.
Claims
An enzymatic assay comprising contacting a solution of an analyte in a solution of a redox reaction mediator with a bed of immobilised enzyme which includes at least a peroxidase and electrochemically determining the concentration of the analyte by monitoring of the redox reaction.
2. An assay as claimed in claim 1, in which the redox reaction mediator is a metal dicyclopenta¬ dienyl monocarboxylic acid.
3. An assay as claimed in claim 2, in which the redox reaction mediator is ferrocene monocarboxylic acid.
An assay as claimed in any preceding claim, in which the redox reaction is monitored by means of a wall jet electrode.
5. An assay, as claimed in any preceding claim, in which the analyte is choline, the immobilised enzyme is choline esterase and the peroxidase is horseradish peroxidase.
6. An assay for the co-determination of choline and acetylcholine, as claimed in claim 5, in which the enzyme bed also contains acetylcholinesterase.
7. An assay as claimed in claim 1, in which the analyte is glucose and the enzyme bed contains glucose oxidase and horseradish peroxidase.
8. An assay as claimed in any preceding claim, in which the analyte is the eluate from a chro ato- graphic column wherein components amenable to detection by the assay are preseparated.
9. A method for the assaying of choline and acetylcholine, comprising separating the choline and acetylcholine chromatographically using an eluant containing, in solution, a redox mediator, delivering the eluate continuously to a bed of immobilised enzyme containing choline oxidase, acetylcholinesterase and horseradish peroxidase, and delivering the effluent stream from the enzyme bed to a wall jet electrode for electrochemical determination of the components.
10. A method as claimed in claim 9, in which the choline oxidase and the acetylcholinesterase are immobilised on aminopropyl-activated glass beads and the horseradish peroxidase on Sepharose (Trade Mark) .
11. A method as claimed in claim 10, in which the immobilised enzymes are present in the bed as a series of alternating layers of said glass-bound and said Sepharose-bound enzymes.
12. Apparatus for conducting an enzymatic assay comprising in serial connection for throughflow of liquid an HPLC column a packed enzyme bed and a wall jet electrode.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8718304 | 1987-08-03 | ||
| GB878718304A GB8718304D0 (en) | 1987-08-03 | 1987-08-03 | Enzymatic assay |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1989001047A1 true WO1989001047A1 (en) | 1989-02-09 |
Family
ID=10621718
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/GB1988/000641 WO1989001047A1 (en) | 1987-08-03 | 1988-08-03 | Enzymatic assay |
Country Status (2)
| Country | Link |
|---|---|
| GB (1) | GB8718304D0 (en) |
| WO (1) | WO1989001047A1 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0422623A2 (en) * | 1989-10-13 | 1991-04-17 | Gesellschaft für Biotechnologische Forschung mbH (GBF) | Enzymatic electrode and its use |
| DE4300362C1 (en) * | 1993-01-08 | 1994-03-24 | Joachim Willms | Analytical appts for enzymatic determn of lactate or glucose content of sample esp blood - with inlet and outlet pipes for sample and feed pipe for additional liq |
| WO1995016198A1 (en) * | 1993-12-08 | 1995-06-15 | Unilever Plc | Methods and apparatus for electrochemical measurements |
| WO1998029738A1 (en) * | 1996-12-28 | 1998-07-09 | Wilkins Ebatisam S | Potentiometric electrode and measuring procedure for determination of organophosphorus compounds |
| WO1998050575A1 (en) * | 1997-05-01 | 1998-11-12 | G.D. Searle & Co. | Method and apparatus for preparation of chiral beta amino acids |
| WO2002097417A1 (en) * | 2001-06-01 | 2002-12-05 | Ecole Centrale De Lyon | Electro-enzymatic method by inhibition for the detection of steroidal glycoalkaloids |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0150999A2 (en) * | 1984-01-26 | 1985-08-07 | Serono Diagnostics Limited | Methods of Assay |
| JPS6188898A (en) * | 1984-10-05 | 1986-05-07 | Yanagimoto Seisakusho:Kk | Simultaneous analysis of acetylcholine and choline by electrochemical detector using immobilized enzyme column |
| WO1986004926A1 (en) * | 1985-02-21 | 1986-08-28 | Genetics International Inc. | Assay for degradable substrates by electrochemical detection of redox species |
| DE3530076A1 (en) * | 1985-08-22 | 1987-02-26 | Max Planck Gesellschaft | METHOD FOR DETECTING COMPOUNDS THAT CAN BE DELIVERED OR INCLUDED BY ENZYME ELECTRONES |
| WO1987002464A1 (en) * | 1985-10-14 | 1987-04-23 | Genetics International (Uk) Inc. | Enzyme-labelled assay |
-
1987
- 1987-08-03 GB GB878718304A patent/GB8718304D0/en active Pending
-
1988
- 1988-08-03 WO PCT/GB1988/000641 patent/WO1989001047A1/en unknown
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0150999A2 (en) * | 1984-01-26 | 1985-08-07 | Serono Diagnostics Limited | Methods of Assay |
| JPS6188898A (en) * | 1984-10-05 | 1986-05-07 | Yanagimoto Seisakusho:Kk | Simultaneous analysis of acetylcholine and choline by electrochemical detector using immobilized enzyme column |
| WO1986004926A1 (en) * | 1985-02-21 | 1986-08-28 | Genetics International Inc. | Assay for degradable substrates by electrochemical detection of redox species |
| DE3530076A1 (en) * | 1985-08-22 | 1987-02-26 | Max Planck Gesellschaft | METHOD FOR DETECTING COMPOUNDS THAT CAN BE DELIVERED OR INCLUDED BY ENZYME ELECTRONES |
| WO1987002464A1 (en) * | 1985-10-14 | 1987-04-23 | Genetics International (Uk) Inc. | Enzyme-labelled assay |
Non-Patent Citations (5)
| Title |
|---|
| CHEMICAL ABSTRACTS, Vol. 103, Number 23, 9 December 1985, F.P. BYMASTER et al., "Measurement of Acetylcholine and Choline in Brain by HPLC with Electrochemical Detection", Abstract No. 192712y; & LIFE SCI., 1985, 37(19), 1775-81. * |
| CHEMICAL ABSTRACTS, Vol. 104, Number 2, 13 January 1986, Y. TOSHIO et al., "HPLC Determination of Acetylcholine and Choline by Use of an Immobilized Enzyme Detector", Abstract No. 14277y; & NIPPON KOGAKU KAISHI, 1985, 7, 1501-3. * |
| CHEMICAL ABSTRACTS, Vol. 104, Number 5, 3 February 1986, Y. TOSHIO et al., "Amperometric Detection of Acetylcholine and Choline in a Liquid Chromatographic System with an Immobilized Enzym Reactor", Abstract No. 31251c; & ANAL. CHIM. ACTA., 1985, 172, 371-5. * |
| CHEMICAL ABSTRACTS, Vol. 89, Number 1, 3 July 1978, R. EPTON et al., "Oxidation of Ferrocene and Some Substituated Ferrocenes in the Presence of Horseradish Peroxidase", Abstract No. 2216m; & J. ORGANOMET. CHEM., 1978, 149(2), 231-44. * |
| PATENT ABSTRACTS OF JAPAN, Vol. 10, No. 262; & JP,A,61 088 898 (YANAGIMOTO SISAKUSHO KK) 7 May 1986. * |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0422623A2 (en) * | 1989-10-13 | 1991-04-17 | Gesellschaft für Biotechnologische Forschung mbH (GBF) | Enzymatic electrode and its use |
| EP0422623A3 (en) * | 1989-10-13 | 1991-06-12 | Gesellschaft Fuer Biotechnologische Forschung Mbh (Gbf) | Enzymatic electrode and its use |
| DE4300362C1 (en) * | 1993-01-08 | 1994-03-24 | Joachim Willms | Analytical appts for enzymatic determn of lactate or glucose content of sample esp blood - with inlet and outlet pipes for sample and feed pipe for additional liq |
| EP0605894A1 (en) * | 1993-01-08 | 1994-07-13 | Joachim Willms | Analytical device for determining the content of lactate resp. glucose |
| WO1995016198A1 (en) * | 1993-12-08 | 1995-06-15 | Unilever Plc | Methods and apparatus for electrochemical measurements |
| TR28318A (en) * | 1993-12-08 | 1996-04-24 | Unilever Nv | Methods and devices for electrochemical measurements. |
| US5645709A (en) * | 1993-12-08 | 1997-07-08 | Van Den Bergh Foods Co., Division Of Conopco, Inc. | Methods and apparatus for electrochemical measurements |
| WO1998029738A1 (en) * | 1996-12-28 | 1998-07-09 | Wilkins Ebatisam S | Potentiometric electrode and measuring procedure for determination of organophosphorus compounds |
| WO1998050575A1 (en) * | 1997-05-01 | 1998-11-12 | G.D. Searle & Co. | Method and apparatus for preparation of chiral beta amino acids |
| US6214609B1 (en) | 1997-05-01 | 2001-04-10 | Monsanto Company | Method and apparatus for preparation of chiral beta amino acids using penicilln G acylase |
| WO2002097417A1 (en) * | 2001-06-01 | 2002-12-05 | Ecole Centrale De Lyon | Electro-enzymatic method by inhibition for the detection of steroidal glycoalkaloids |
| FR2825374A1 (en) * | 2001-06-01 | 2002-12-06 | Lyon Ecole Centrale | ELECTRO-ENZYMATIC INHIBITION PROCESS FOR THE DETECTION OF STEROID GLYCOALCALOIDS |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8718304D0 (en) | 1987-09-09 |
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