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Park S, Lee H, Yang H. Sensitive Affinity-Based Biosensor Using the Autocatalytic Activation of Trypsinogen Mutant by Trypsin with Low Self-activation. ACS APPLIED BIO MATERIALS 2022; 5:4516-4522. [PMID: 35972302 DOI: 10.1021/acsabm.2c00594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Self-propagating autocatalytic reactions of proteases that can provide high signal amplification have not been applied to affinity-based biosensors owing to the limited number of fast autocatalytic proteolytic reactions available and the self-activation of protease proenzymes. Here, we report that a self-propagating autocatalytic reaction based on the autocatalytic activation of the trypsinogen mutant by trypsin facilitates high signal amplification and a low background level, resulting in a low detection limit for prostate-specific antigen (PSA). A commercially available trypsinogen mutant minimizes the self-activation of trypsinogen by trypsinogen. Trypsin, which is used as a catalytic label in a sandwich-type immunosensor, converts the trypsinogen mutant into trypsin; the generated trypsin then further converts the trypsinogen mutant into trypsin. The autocatalytically produced trypsin proteolytically cleaves the peptide bond of a trypsin substrate, resulting in the liberation of electrochemically active 4-aminophenol (AP). The electrochemical oxidation of AP at a modified indium tin oxide (ITO) electrode induces electrochemical-chemical redox cycling involving the ITO electrode, AP, and a reductant. The triple combination of autocatalytic activation, proteolytic cleavage, and redox cycling results in a high electrochemical signal level. The detection limit for PSA obtained using a trypsin label and trypsinogen (∼7 pg/mL) is lower than that obtained using a trypsin label alone (∼100 pg/mL). This study demonstrated that autocatalytically activating a proenzyme is a very useful method for highly amplifying signals.
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Affiliation(s)
- Seonhwa Park
- Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan 46241, Korea
| | - Hyoeun Lee
- Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan 46241, Korea
| | - Haesik Yang
- Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan 46241, Korea
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2
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An amplification-free method for the detection of HOTAIR long non-coding RNA. Anal Chim Acta 2020; 1132:66-73. [DOI: 10.1016/j.aca.2020.07.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 07/13/2020] [Accepted: 07/15/2020] [Indexed: 01/06/2023]
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3
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Yang H. Enzyme-based ultrasensitive electrochemical biosensors. Curr Opin Chem Biol 2012; 16:422-8. [PMID: 22503680 DOI: 10.1016/j.cbpa.2012.03.015] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 03/23/2012] [Indexed: 12/20/2022]
Abstract
Signal amplification in conventional enzyme-based biosensors is not high enough to achieve the ultrasensitive detection of biomolecules. In recent years, signal amplification has been improved by combining enzymatic reactions with redox cycling or employing multienzyme labels per detection probe. Electrochemical-chemical redox cycling and electrochemical-chemical-chemical redox cycling allow ultrasensitive detection simply by including one or two more chemicals in a solution without the use of an additional enzyme and/or electrode. Multiple horseradish peroxidase labels on magnetic bead carriers provide high signal enhancement along with a multiplex detection possibility. In both cases, the detection procedures are the same as those in conventional enzyme-based electrochemical sensors.
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Affiliation(s)
- Haesik Yang
- Department of Chemistry and Chemistry Institute of Functional Materials, Pusan National University, Busan 609-735, Republic of Korea.
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4
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Virel A, Saa L, Pavlov V. Quantification of prothrombin in human plasma amplified by autocatalytic reaction. Anal Chem 2012; 84:2380-7. [PMID: 22324776 DOI: 10.1021/ac203138y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
By site directed mutagenesis, we have produced recombinant mutants of human and mouse prethrombin-2 which are able to convert themselves autocatalytically into α-thrombin. We also have created a new method to amplify the signal of bioanalytical assays based on the autocatalytic activation of these mutated proenzymes. The activation of the mutants by active α-thrombin triggers an autocatalytic reaction which leads to more active thrombin resulting in the amplification of the readout signal. Addition of mutated mouse prethrombin-2 into the conventional assay for prothrombin level in human plasma, employing ecarin and the fluorogenic substrate, resulted in improvement of the detection limit by 2 orders of magnitude.
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Affiliation(s)
- Ana Virel
- CIC biomaGUNE, Parque Tecnológico de San Sebastián, Paseo Miramón 182, 20009, San Sebastián, Spain
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5
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Saha D, Acharya D, Roy D, Dhar TK. Filtration-based tyramide amplification technique—a new simple approach for rapid detection of aflatoxin B1. Anal Bioanal Chem 2006; 387:1121-30. [PMID: 17151856 DOI: 10.1007/s00216-006-0943-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2006] [Revised: 10/11/2006] [Accepted: 10/12/2006] [Indexed: 11/29/2022]
Abstract
The catalyzed reporter deposition (CARD) method of signal amplification, also called "tyramide signal amplification", has been used in immunoassays not only to increase sensitivity but also to reduce assay time. The current approach to tyramide amplification in immunoassays involves slow incubation with agitation. In this paper we describe new filtration-based tyramide amplification and substrate visualization techniques. Compared with the standard method, this new approach greatly enhances spot intensities in membrane immunoassay and reduces biotinylated tyramide (B-T) and substrate consumption approximately fiftyfold, without loss of specificity. An improved test device and a cost-effective method for preparation of membranes for Super-CARD amplification have also been developed. The techniques have been used for rapid detection of aflatoxin B(1) (AFB(1)) in a variety of foodstuffs with a detection limit of 12.5 microg kg(-1). The assay procedure involves sequential addition of standards or sample, AFB(1)-horseradish peroxidase (HRP) conjugate, B-T, avidin-HRP, and substrate solution over anti-AFB(1) antibody-spotted zones of the membrane surface. The method saves time, improves reproducibility, eliminates many washing steps and avoids manipulation of the membranes between the different steps, while maintaining the sensitivity of the standard method. Average recoveries from different non-infected food samples spiked with AFB(1) at concentrations from 25 to 100 mg kg(-1) were between 95 and 105%. AFB(1) results obtained on different days for Aspergillus parasiticus infection of corn and groundnut samples correlated well with estimates obtained by HPLC.
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Affiliation(s)
- Debjani Saha
- Drug Development, Diagnostics and Biotechnology Division, Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Calcutta, 700 032, India
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6
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Warsinke A, Nagel B. Towards Separation‐Free Electrochemical Affinity Sensors by Using Antibodies, Aptamers, and Molecularly Imprinted Polymers—A Review. ANAL LETT 2006. [DOI: 10.1080/00032710600853903] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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7
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Warsinke A, Stöcklein W, Leupold E, Micheel E, Scheller FW. Electrochemical Immunosensors on the Route to Proteomic Chips. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s1871-0069(05)01014-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
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8
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Kania M, Hock B. DEVELOPMENT OF MONOCLONAL ANTIBODIES TO DOMOIC ACID FOR THE DETECTION OF DOMOIC ACID IN BLUE MUSSEL (MYTILUS EDULIS) TISSUE BY ELISA. ANAL LETT 2002. [DOI: 10.1081/al-120004074] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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9
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Marx A, Sherry J, Hansen PD, Hock B. A new monoclonal antibody against vitellogenin from rainbow trout (Oncorhynchus mykiss). CHEMOSPHERE 2001; 44:393-399. [PMID: 11459144 DOI: 10.1016/s0045-6535(00)00351-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Monoclonal antibodies were developed against vitellogenin (vtg) of rainbow trout. This protein is used as a biochemical response to the exposure with estrogenic compounds. Several mice were immunized with purified vtg and the spleen cells of these mice were fused with myeloma cells. The resulting hybridoma cells were screened with an enzyme immunoassay for the production of specific anti-vtg antibodies. Twelve positive cell lines were detected. The hybridoma cell line B8D8 was adjusted to serum free medium; it produced monoclonal antibodies with a high selectivity and sensitivity. A detection limit of 5 microg/l vtg was achieved with a competitive enzyme immunoassay applying a preincubation step and a streptavidin-biotin amplification system (ABC system). Cross-reactivity with vtg of other species was detected with roach (Rutilus rutilus), flounder (Platichthys flesus) and dab (Limanda limanda). The assay was applied to rainbow trout (Oncorhynchus mykiss), which were exposed for six months to defined concentrations of effluents (10%, 20%, 30% and 40%) and surface water. Increased vtg levels in male fish are correlated with the increasing levels of effluent. The effluent levels in the exposure experiments are relevant for effluent loadings of the Berlin waterways during the seasons of the year.
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Affiliation(s)
- A Marx
- Department of Botany, Technische Universität of München, Freising, Germany
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10
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Bhattacharya D, Bhattacharya R, Dhar TK. A novel signal amplification technology for ELISA based on catalyzed reporter deposition. Demonstration of its applicability for measuring aflatoxin B(1). J Immunol Methods 1999; 230:71-86. [PMID: 10594355 DOI: 10.1016/s0022-1759(99)00124-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In an earlier communication we have described a novel signal amplification technology termed Super-CARD, which is able to significantly improve antigen detection sensitivity in conventional Dot-ELISA by approximately 10(5)-fold. The method utilizes hitherto unreported synthesized electron rich proteins containing multiple phenolic groups which, when immobilized over a solid phase as blocking agent, markedly increases the signal amplification capability of the existing CARD method (Bhattacharya, R., Bhattacharya, D., Dhar, T.K., 1999. A novel signal amplification technology based on catalyzed reporter deposition and its application in a Dot-ELISA with ultra high sensitivity. J. Immunol. Methods 227, 31.). In this paper we describe the utilization of this Super-CARD amplification technique in ELISA and its applicability for the rapid determination of aflatoxin B(1) (AFB(1)) in infected seeds. Using this method under identical conditions, the increase in absorbance over the CARD method was approximately 400%. The limit of detection of AFB(1) by this method was 0.1 pg/well, the sensitivity enhancement being 5-fold over the optimized CARD ELISA. Furthermore, the total incubation time was reduced to 16 min compared to 50 min for the CARD method. Assay specificity was not adversely affected and the amount of AFB(1) measured in seed extracts correlated well with the values obtained by conventional ELISA.
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Affiliation(s)
- D Bhattacharya
- Indian Institute of Chemical Biology, 4 Raja S C Mullick Road, Jadavpur, Calcutta, India
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11
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Luo D, Geng M, Schultes B, Ma J, Xu DZ, Hamza N, Qi W, Noujaim AA, Madiyalakan R. Expression of a fusion protein of scFv-biotin mimetic peptide for immunoassay. J Biotechnol 1998; 65:225-8. [PMID: 9828463 DOI: 10.1016/s0168-1656(98)00094-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We constructed two fusion proteins of scFv linked to biotin mimetic sequence (BMS) via different linkers, and expressed them in the Pichia pastoris expression/secretion system. We found that both bi-functional scFv proteins exhibited their intrinsic binding activities to antigen CA125 determined in competitive radioimmunoassay experiments, but the fusion protein with a spacer between the scFv and BMS (scFv-spacer-BMS) showed higher binding activity of streptavidin than the one with c-Myc peptide as a linker.
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Affiliation(s)
- D Luo
- Research and Development, AltaRex Corp., University of Alberta, Edmonton, Canada
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12
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Lapierre AV, Olsina RA, Raba J. Continuous-Flow/Stopped-Flow and Rotating Bioreactors in the Determination of Glucose. Anal Chem 1998; 70:3679-84. [DOI: 10.1021/ac9708194] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alicia V. Lapierre
- Department of Analytical Chemistry, National University of San Luis, Chacabuco y Pedernera, C.P.(5.700), San Luis, Argentina
| | - Roberto A. Olsina
- Department of Analytical Chemistry, National University of San Luis, Chacabuco y Pedernera, C.P.(5.700), San Luis, Argentina
| | - Julio Raba
- Department of Analytical Chemistry, National University of San Luis, Chacabuco y Pedernera, C.P.(5.700), San Luis, Argentina
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13
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Goldschmidt PL, Devillechabrolle A, Ait-Arkoub Z, Aubin JT. Comparison of an amplified enzyme-linked immunosorbent assay with procedures based on molecular biology for assessing human immunodeficiency virus type 1 viral load. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1998; 5:513-8. [PMID: 9665959 PMCID: PMC95610 DOI: 10.1128/cdli.5.4.513-518.1998] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The sensitivity of the enzyme-linked amplified sorbent test (ELAST) was compared with those of other classic enzyme-linked immunosorbent assays (ELISAs), with or without previous acidic immunocomplex dissociation (ICD), in a series of samples at different stages of human immunodeficiency virus type 1 (HIV-1) infection. The limit of viral detection of ELAST was assessed with fresh HIV-1 preparations quantified by reverse transcription-PCR and with the P24 antigen (Ag) Sanofi Pasteur Calibrator containing lyophilized virus. The P24 Ag detection capacity of ELAST was compared with that of NASBA in samples obtained from infected subjects with less than 250 CD4+ cells. The results of the present study show that ELAST was the most sensitive method for detecting P24 Ag compared to classic ELISA and ICD plus ELISA. ELAST was able to detect 0.5 pg of P24 Ag per ml in a whole virus preparation and the equivalent of 330 to 1,000 RNA copies/ml of HIV. The rate of detection of P24 Ag was always higher in subjects with low levels of anti-P24 antibodies. The number of positive results was dramatically enhanced (from 37% to 94% for subjects with <250 CD4+ cells) when the incubation period was prolonged from 1 to 16 h. In a third series of 84 samples (<250 CD4+ cells) tested in parallel, NASBA yielded 83% of the positive results and ELAST yielded 79%. Considering the high sensitivity, low cost, simplicity of equipment (only a plate reader), and possibility for full automation, ELAST appears to be a promising new tool for measuring viral load, especially in areas with few resources, in which the procedures based on molecular biology techniques may be difficult to install.
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Affiliation(s)
- P L Goldschmidt
- CERVI-VIROLOGIE, Centre Hospitalier Universitaire Pitié-Salpêtrière, Paris, France.
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14
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Marx A, Krˇtz E, Hock B. Improvement of an Enzyme Immunoassay for the Determination of Mercury(II). ANAL LETT 1998. [DOI: 10.1080/00032719808005249] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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15
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Saini PK, Webert DW, Judkins JC. Role of sodium azide in reducing nonspecific color development in enzyme immunoassays. J Vet Diagn Invest 1995; 7:509-14. [PMID: 8580174 DOI: 10.1177/104063879500700415] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Improved enzyme immunoassay (EIA) procedures achieved by incorporating sodium azide during predilution of serum samples in a solid-phase EIA for the detection of anti-Toxoplasma antibody in swine using a peroxidase conjugate and in all washes of a bovine brucellosis rapid card test EIA using alkaline phosphatase conjugate are reported. Without this modification, substantial background interference was encountered that showed direct correlation with the degree of hemolysis of the serum samples. Anti-Toxoplasma gondii antibody-negative samples, separated by subjective groupings based on degree of hemolysis, into "clear", "slight", and "gross/total" samples, had a mean +/- standard deviation of 0.150 +/- 0.072, 0.187 +/- 0.105, and 0.232 +/- 0.108, respectively. The incorporation of sodium azide during the initial step of serum dilution dramatically eliminated the background, giving a mean +/- standard deviation of 0.079 +/- 0.029, 0.076 +/- 0.022, and 0.081 +/- 0.029, respectively. The level of endogenous peroxidase activity, a possible factor for this nonspecific interference, was considerably elevated in some of the swine sera. The clear, slight, and gross/total categories had relative levels of 1%, 2%, and 51% peroxidase activity compared to the conjugate peroxidase activity of 100%. Whereas sodium azide could be used only in sample predilution in the swine toxoplasmosis peroxidase-conjugate test, in the bovine brucellosis alkaline phosphatase-conjugate card test it could be used in all wash cycles. Many brucellosis card test results were visually uninterpretable because of significant background color when the manufacturer's wash reagent was used. The substitution of a wash reagent containing sodium azide eliminated background color, giving a visually unambiguous test.
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Affiliation(s)
- P K Saini
- Serology Branch, U.S. Department of Agriculture, Beltsville, MD 20705, USA
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16
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Fisher M, Harbron S, Eggelte HJ, Rabin BR. Purification and semienzymic synthesis of flavin adenine dinucleotide-3'-phosphate. Enzyme Microb Technol 1994; 16:281-5. [PMID: 7765339 DOI: 10.1016/0141-0229(94)90167-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Nonradioactive immunoassays incorporating an element of amplification in their detection system require the use of components that are highly purified. Flavin adenine dinucleotide-3'-phosphate (FADP) is the primary substrate used in such an amplification assay. For incorporation into a simple, single-pot assay system, the concentration of contaminating flavin adenine dinucleotide (a prosthetic group for the enzyme D-aminoacid oxidase used in the amplification cascade assay) in this primary substrate must be minimized to achieve maximum sensitivity. Production of the substrate to a high degree of purity has been achieved using apo-glucose oxidase to specifically remove contaminating flavin adenine dinucleotide from solution and hydrolysis of a cyclic intermediate as a final production protocol by ribonuclease T2 to give the product in high yield. The use of continuous ultrafiltration reactors at each stage is described and compared to a final production step utilizing immobilized ribonuclease T2. These reactors allow large volumes of material to be handled and assist in the scale-up of these processes. The suitability of each protocol is assessed for the commercial production of FADP.
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Affiliation(s)
- M Fisher
- London Biotechnology Limited, Department of Biochemistry and Molecular Biology, University College London, UK
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17
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Gudibande SR, Kenten JH, Link J, Friedman K, Massey RJ. Rapid, non-separation electrochemiluminescent DNA hybridization assays for PCR products, using 3'-labelled oligonucleotide probes. Mol Cell Probes 1992; 6:495-503. [PMID: 1480189 DOI: 10.1016/0890-8508(92)90046-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Described are rapid assays for the analysis of PCR products in a one step, non-separation assay based on the use of electrochemiluminescence generated from a tris-bipyridine ruthenium (II) label. The assay uses PCR incorporation of a biotinylated oligonucleotide as a primer, with the inclusion of a labelled oligonucleotide. Oligonucleotides were labelled with an N-hydroxy succinimide ester of tris-bipyridine ruthenium (II) dihexafluorophosphate (Origen-label) by modifying the 3' and 3' 5' ends of the oligonucleotide probes. The assay makes use of the inherent thermal stability and absence of polymerase activity on such probes to allow the PCR and probe hybridization to be completed automatically on the thermocycler. The assay is concluded by the addition of PCR samples to streptavidin beads on an electrochemiluminescence analyser for binding and analysis. Target genes evaluated were the HIV-1 gag gene, and cystic fibrosis delta F-508 deletion mutation. The results obtained from these assays demonstrated the detection of 10 copies of the HIV-1 gag gene, and cystic fibrosis delta F-508 mutation in 1 ng of human DNA within 15 min. This assay format allows a rapid and simple determination of specific amplified DNA sequences, reducing the contamination risks due to washes and multiple pipetting.
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Affiliation(s)
- S R Gudibande
- Department of Molecular Biology, IGEN Inc., Rockville, MD 20852
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18
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Bystryak SM, Mekler VM. Photochemical amplification for horseradish peroxidase-mediated immunosorbent assay. Anal Biochem 1992; 202:390-3. [PMID: 1519767 DOI: 10.1016/0003-2697(92)90123-o] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A new method for lowering the detection limit for a horseradish peroxidase (HRP) label in an enzyme-linked immunosorbent assay (ELISA) is proposed. The method is based on the use of a photochemical reaction of o-phenylenediamine (o-PD) autosensitized oxidation as an enhancement step in ELISA. The assay consists of two successive steps. The first step is a conventional HRP-mediated ELISA, using high-purity o-PD as a substrate. At this step, an o-PD oxidation product, 2,3-diaminophenazine (DAP), is formed in the dark. At the second step, the sample is illuminated at 400-500 nm for several minutes. Under illumination the concentration of DAP is greatly increased, depending on the duration and intensity of irradiation. Providing that the irradiation conditions are standardized, the final DAP concentration is proportional to the concentration of DAP formed by HRP. An ELISA for human carcinoembryonic antigen has demonstrated that the photochemical amplification method allows the detection limit of an assayed antigen to be lowered and the consumption of antibodies to be reduced. At the second step of this assay, the DAP concentration has been increased 50-fold under 4 min of irradiation.
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Affiliation(s)
- S M Bystryak
- Institute of Chemical Physics, Chernogolovka, Moscow Region, USSR
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19
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Lindbladh C, Mosbach K, Bülow L. Preparation of a genetically fused protein A/luciferase conjugate for use in bioluminescent immunoassays. J Immunol Methods 1991; 137:199-207. [PMID: 2013697 DOI: 10.1016/0022-1759(91)90025-b] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The genes encoding staphylococcal protein A and bacterial luciferase (Vibrio harveyi) were fused in-frame in order to obtain a general marker enzyme for bioluminescent immunoassays. Two constructs were made where protein A was ligated to the first and the 12th amino acid residue, respectively, of the N terminus of the beta subunit of luciferase. Only the first fusion protein encoding the entire beta subunit was able to form an enzymatically active luciferase complex when expressed together with the alpha subunit. The fusion of protein A to luciferase did not notably alter the emitted wavelength spectrum or its stability to urea treatment. The fusion protein was found to retain at least 50% of the specific bioluminescent activity compared to native luciferase. In preliminary tests, this hybrid protein was shown to be useful in bioluminescent immunoassays.
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Affiliation(s)
- C Lindbladh
- Department of Pure and Applied Biochemistry, University of Lund, Sweden
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20
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Bobrow MN, Shaughnessy KJ, Litt GJ. Catalyzed reporter deposition, a novel method of signal amplification. II. Application to membrane immunoassays. J Immunol Methods 1991; 137:103-12. [PMID: 1849153 DOI: 10.1016/0022-1759(91)90399-z] [Citation(s) in RCA: 177] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In a previous publication (Bobrow et al., J. Immunol. Methods (1989) 279-285), we described a novel signal amplification method, catalyzed reporter deposition (CARD), and its application to microplate immunoassays. The method utilizes the analyte-dependent reporter enzyme (ADRE) to catalyze the deposition of additional reporter onto the surface of a solid-phase immunoassay system. In this paper, we describe the utilization of CARD amplification for nonradiometric membrane assays where detection is facilitated by the formation of an insoluble chromogenic product. In the examples described, deposition of reporter is accomplished in two steps: (i) a horseradish peroxidase (HRP) ADRE catalyzes the deposition of either a biotin or fluorescein labeled phenol, and (ii) incubation with either enzyme labeled streptavidin or anti-fluorescein, respectively, results in the deposition of additional enzyme. Using this method, we have improved detection limits from 8- to greater than 200-fold depending on the amplification format and the chromogen used.
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Affiliation(s)
- M N Bobrow
- Medical Products Department, E.I. Du Pont De Nemours & Co., North Billerica, MA 01862
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21
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Hunger HD, Schmidt G, Flachmeier C, Behrendt G, Coutelle C. High-sensitivity protein detection by a new "contact-copy" method using a protein A-neomycin phosphotransferase II fusion protein. Anal Biochem 1990; 186:159-64. [PMID: 2162634 DOI: 10.1016/0003-2697(90)90590-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A new system for high-sensitivity protein detection by an immunoenzymatic "contact-copy" procedure is described. It is based on two components: (i) a microbiologically produced bifunctional fusion protein of protein A and neomycin phosphotransferase II (protein A-NPT II) in which the protein A moiety acts as a second immunological reagent while NPT II catalyzes the detection reaction and (ii) a novel kanamycin-loaded substrate matrix (kanamycin-cyanuric chloride-activated and sulfanilic acid-derivatized paper) brought into direct contact with a protein-carrying matrix after blot or dot application and initial immunoreaction--the NPT II enzyme reaction with [gamma-32P]ATP as cosubstrate leads to phosphorylation of the substrate kanamycin on the substrate matrix, which is used for further analysis. The contact-copy method has at least the same detection sensitivity as procedures employing 125I-protein A, but allows extremely short exposure times and avoids probe prelabeling. Twenty-five picograms of specific protein blotted from sodium dodecyl sulfate-polyacrylamide gels onto nitrocellulose is detected after 15 min of autoradiography. The limit of detection in dot tests was found to be 10 pg per dot (3 mm2). The method is suitable for quantitative determination of antigens in the range down to 100 pg. Several contact copies of the same original protein-carrying matrix can be produced and used for detection or quantitative analysis without destroying the original matrix.
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Affiliation(s)
- H D Hunger
- Academy of Sciences, Central Institute of Molecular Biology, Department of Human Molecular Genetics, Berlin, German Democratic Republic
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Bobrow MN, Harris TD, Shaughnessy KJ, Litt GJ. Catalyzed reporter deposition, a novel method of signal amplification. Application to immunoassays. J Immunol Methods 1989; 125:279-85. [PMID: 2558138 DOI: 10.1016/0022-1759(89)90104-x] [Citation(s) in RCA: 509] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A novel signal amplification method, catalyzed reporter deposition (CARD), and its application to immunoassays is described. The method involves utilizing an analyte-dependent reporter enzyme (ADRE) to catalyze the deposition of additional reporter on the surface in a solid-phase immunoassay. In the examples described, deposition of reporter is facilitated by using a horseradish peroxidase (HRP) ADRE to catalyze the deposition of biotin labeled phenols. The deposited biotins are then reacted with streptavidin-labeled enzyme, thereby resulting in deposition of enzyme. Using the ADRE to catalyze the deposition of additional enzyme results in an amplification of the signal of the ADRE alone and improves the detection limit of the assay. The method is highly sensitive, simple, flexible, and easy to implement.
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Affiliation(s)
- M N Bobrow
- Medical Products Department, E.I. Du Pont De Nemours & Co., North Billerica, MA 01862
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23
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Chu P, Waterhouse P, Martin R, Gerlach W. New Approaches to the Detection of Microbial Plant Pathogens. Biotechnol Genet Eng Rev 1989. [DOI: 10.1080/02648725.1989.10647856] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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24
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Homogeneous amperometric ligand-binding assay amplified by a proteolytic enzyme cascade. ACTA ACUST UNITED AC 1989. [DOI: 10.1016/0022-0728(89)80239-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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25
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Abstract
This paper describes a method to enhance the sensitivity of enzyme immunoassays by the use of solid tagged latex beads. Various bead sizes (0.21 and 0.81 micron) were tested using particles which had been covalently modified (or coated) with biotinylated rabbit anti-mouse immunoglobulin antibodies. Detection limits of mouse monoclonal antibodies or antigens (which have been reacted with specific mouse antibodies) were compared to those obtained using the general homogeneous 'sandwich' ELISA assay. Compared to the homogeneous biotin-avidin ELISA an increase in sensitivity level of about 6-10 times was observed in antigen detection assays. The stability of the reagent was excellent. The method gave low backgrounds and was as simple to use as the standard procedure.
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Affiliation(s)
- B Nilsson
- Research and Development, Carbohydrates International AB, Arlöv, Sweden
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