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Ray SK. TUNEL-n-DIFL Method for Detection and Estimation of Apoptosis Specifically in Neurons and Glial Cells in Mixed Culture and Animal Models of Central Nervous System Diseases and Injuries. Methods Mol Biol 2024; 2761:1-26. [PMID: 38427225 DOI: 10.1007/978-1-0716-3662-6_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Detection of merely apoptosis does not reveal the type of central nervous system (CNS) cells that are dying in the CNS diseases and injuries. In situ detection and estimation of amount of apoptosis specifically in neurons or glial cells (astrocytes, oligodendrocytes, and microglia) can unveil valuable information for designing therapeutics for protection of the CNS cells and functional recovery. A method was first developed and reported from our laboratory for in situ detection and estimation of amount of apoptosis precisely in neurons and glial cells using in vitro and in vivo models of CNS diseases and injuries. This is a combination of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and double immunofluorescent labeling (DIFL) or simply TUNEL-n-DIFL method for in situ detection and estimation of amount of apoptosis in a specific CNS cell type. An anti-digoxigenin (DIG) IgG antibody conjugated with 7-amino-4-methylcoumarin-3-acetic acid (AMCA) for blue fluorescence, fluorescein isothiocyanate (FITC) for green fluorescence, or Texas Red (TR) for red fluorescence can be used for in situ detection of apoptotic cell DNA, which is earlier labeled with TUNEL using alkali-stable DIG-11-dUTP. A primary anti-NeuN (neurons), anti-GFAP (astrocytes), anti-MBP (oligodendrocytes), or anti-OX-42 (microglia) IgG antibody and a secondary IgG antibody conjugated with one of the above fluorophores (other than that of ani-DIG antibody) are used for in situ detection of apoptosis in a specific CNS cell type in the mixed culture and animal models of the CNS diseases and injuries.
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Affiliation(s)
- Swapan K Ray
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, SC, USA.
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Schmidt AJ, Mayer JU, Wallace PK, Ronchese F, Price KM. Simultaneous Polychromatic Immunofluorescent Staining of Tissue Sections and Consecutive Imaging of up to Seven Parameters by Standard Confocal Microscopy. ACTA ACUST UNITED AC 2020; 91:e64. [PMID: 31763771 DOI: 10.1002/cpcy.64] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Confocal microscopy has been an important imaging tool for life scientists for over 20 years. Early techniques focused on indirect staining processes that involved staining with an unconjugated primary antibody, followed by incubation with a secondary fluorescent antibody that would reveal and amplify the signal of the primary antibody. With more and more directly conjugated fluorescent primary antibodies becoming commercially available, staining with multiple fluorescent primary antibodies is now more frequent. To date, staining with up to three primary antibodies and a nuclear dye is widely practiced. Here, we describe an important improvement to the standard polychromatic immunofluorescent staining protocol that allows the simultaneous detection of seven fluorescent parameters using a standard confocal laser scanning microscope with four laser lines and four photomultiplier tubes. By incorporating recently available tandem dyes that emit in the blue and violet regions of the visible light spectrum (Brilliant Blue and Brilliant Violet), we were able to differentiate several additional fluorochromes simultaneously. Due to the added complexity of 7-color immunofluorescent imaging, we developed a clear methodology to optimize antibody concentrations and simple guidelines on how to identify and correct non-specific signals. These are detailed in the following protocol. © 2019 by John Wiley & Sons, Inc. Basic Protocol: 7-Color immunofluorescent staining protocol using directly conjugated antibodies Support Protocol 1: Antibody titration protocol Support Protocol 2: Spillover optimization protocol.
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Affiliation(s)
| | | | - Paul K Wallace
- Department of Flow & Image Cytometry, Roswell Park Comprehensive Cancer Center, Buffalo, New York
| | - Franca Ronchese
- Malaghan Institute of Medical Research, Wellington, New Zealand
| | - Kylie M Price
- Malaghan Institute of Medical Research, Wellington, New Zealand
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Leichner J, Lin WC. Advances in imaging and analysis of 4 fluorescent components through the rat cortical column. J Neurosci Methods 2020; 341:108792. [PMID: 32446942 DOI: 10.1016/j.jneumeth.2020.108792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 05/14/2020] [Accepted: 05/18/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND Immunofluorescent staining coupled with axial optical sectioning allows for assessment of native three-dimensional structure of brain tissue. Typical challenges of analyzing network structure include limitations driven by magnification/field of view, spatial resolution, tissue thickness, staining quality of dense cell types, data quantifiability and the quantity of simultaneous staining targets. NEW METHOD This manuscript demonstrates many methodological advancements. Software-aided alignment of the cortical slice and stereotaxic atlas maximizes ROI-identification accuracy. Tissue compression during antigen retrieval enhances epitope availability without damaging tissue. A thorough factorial experiment focusing on Smi-311 staining highlights the enhancements in image quality from our extended staining protocol. Mosaic scanning techniques and subsequent four-channel alignment ensures high data quality. RESULTS Cortical column datasets [800μm x 3000μm x 70μm] utilizing sequential optical sectioning were successfully generated from three rats. Each rat provided three coronal sections in each of two regions, M1 and S1BF, from which data cubes were generated per hemisphere, totaling 36 high-magnification four-color datasets. COMPARISON WITH EXISTING METHOD(S) Typical confocal assessments of brain tissue do not utilize such thick tissue slices nor collect entire cortical columns from the cortical surface to the grey/white interface at a resolution that can map fine filamentous processes. The simultaneous collection of our four specific structural markers - neuronal, astrocytic, vascular and nuclear - is novel and the quantitative optimization of staining protocols through a factorial design rare. CONCLUSIONS Building upon this preliminary success in protocol development, future work will encompass volumetric modeling and quantitative analysis of regional network architecture.
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Affiliation(s)
- Jared Leichner
- Biomedical Engineering Creative Laboratory, Department of Biomedical Engineering, Florida International University, 10555 West Flagler Street, Miami, FL 33174, USA
| | - Wei-Chiang Lin
- Biomedical Engineering Creative Laboratory, Department of Biomedical Engineering, Florida International University, 10555 West Flagler Street, Miami, FL 33174, USA.
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Fully automated 5-plex fluorescent immunohistochemistry with tyramide signal amplification and same species antibodies. J Transl Med 2017; 97:873-885. [PMID: 28504684 DOI: 10.1038/labinvest.2017.37] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 02/24/2017] [Accepted: 02/25/2017] [Indexed: 12/20/2022] Open
Abstract
The ability to simultaneously visualize the presence, abundance, location and functional state of many targets in cells and tissues has been described as a true next-generation approach in immunohistochemistry (IHC). A typical requirement for multiplex IHC (mIHC) is the use of different animal species for each primary (1°Ab) and secondary (2°Ab) antibody pair. Although 1°Abs from different species have been used with differently labeled species-specific 2°Abs, quite often the appropriate combination of antibodies is not available. More recently, sequential detection of multiple antigens using 1°Abs from the same species used a microwaving treatment between successive antigen detection cycles to elute previously bound 1°Ab/2°Ab complex and therefore to prevent the cross-reactivity of anti-species 2°Abs used in subsequent detection cycles. We present here a fully automated 1°Ab/2°Ab complex heat deactivation (HD) method on Ventana's BenchMark ULTRA slide stainer. This method is applied to detection using fluorophore-conjugated tyramide deposited on the tissue and takes advantage of the strong covalent bonding of the detection substrate to the tissue, preventing its elution in the HD process. The HD process was characterized for (1) effectiveness in preventing Ab cross-reactivity, (2) impact on the epitopes and (3) impact on the fluorophores. An automated 5-plex fluorescent IHC assay was further developed using the HD method and rabbit 1°Abs for CD3, CD8, CD20, CD68 and FoxP3 immune biomarkers in human tissue specimens. The fluorophores were carefully chosen and the narrow-band filters were designed to allow visualization of the staining under fluorescent microscope with minimal bleed through. The automated 5-plex fluorescent IHC assay achieved staining results comparable to the respective single-plex chromogenic IHC assays. This technology enables automated mIHC using unmodified 1°Abs from same species and the corresponding anti-species 2°Ab on a clinically established automated platform to ensure staining quality, reliability and reproducibility.
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O'Hurley G, Sjöstedt E, Rahman A, Li B, Kampf C, Pontén F, Gallagher WM, Lindskog C. Garbage in, garbage out: a critical evaluation of strategies used for validation of immunohistochemical biomarkers. Mol Oncol 2014; 8:783-98. [PMID: 24725481 PMCID: PMC5528533 DOI: 10.1016/j.molonc.2014.03.008] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 03/10/2014] [Indexed: 12/19/2022] Open
Abstract
The use of immunohistochemistry (IHC) in clinical cohorts is of paramount importance in determining the utility of a biomarker in clinical practice. A major bottleneck in translating a biomarker from bench-to-bedside is the lack of well characterized, specific antibodies suitable for IHC. Despite the widespread use of IHC as a biomarker validation tool, no universally accepted standardization guidelines have been developed to determine the applicability of particular antibodies for IHC prior to its use. In this review, we discuss the technical challenges faced by the use of immunohistochemical biomarkers and rigorously explore classical and emerging antibody validation technologies. Based on our review of these technologies, we provide strict criteria for the pragmatic validation of antibodies for use in immunohistochemical assays.
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Affiliation(s)
- Gillian O'Hurley
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland; Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, 751 85 Uppsala, Sweden; OncoMark Ltd, NovaUCD, Belfield Innovation Park, Belfield, Dublin 4, Ireland
| | - Evelina Sjöstedt
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, 751 85 Uppsala, Sweden
| | - Arman Rahman
- OncoMark Ltd, NovaUCD, Belfield Innovation Park, Belfield, Dublin 4, Ireland
| | - Bo Li
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Caroline Kampf
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, 751 85 Uppsala, Sweden
| | - Fredrik Pontén
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, 751 85 Uppsala, Sweden.
| | - William M Gallagher
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland; OncoMark Ltd, NovaUCD, Belfield Innovation Park, Belfield, Dublin 4, Ireland.
| | - Cecilia Lindskog
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, 751 85 Uppsala, Sweden
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Ribarič S, Čebašek V. Simultaneous visualization of myosin heavy chain isoforms in single muscle sections. Cells Tissues Organs 2013; 197:312-21. [PMID: 23306777 DOI: 10.1159/000345424] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/25/2012] [Indexed: 11/19/2022] Open
Abstract
We developed a staining protocol that enables simultaneous visualization of myosin heavy chain (MHC) pure and hybrid muscle fiber types in rat skeletal muscle. Up to eight different muscle fiber types can be visualized in a single section of the rat extensor digitorum longus muscle, which contains all four adult MHC isoforms and shows plasticity during the denervation-reinnervation process. Triple immunofluorescent staining of MHC-1, MHC-2a and MHC-2b with primary antibodies BA-D5 (isotype IgG2b), SC-71 (isotype IgG1) and BF-F3 (isotype IgM) and with three fluorophore-labeled isotype-specific secondary antibodies displays different muscle fiber types in a merged image of red, green and blue channels, each in its own color. Immunoperoxidase staining with primary antibody 6H1 directed against MHC-2x can be additionally applied on the same tissue section to facilitate the identification of muscle fibers containing MHC-2x. Triple staining can also be used in combination with other staining procedures to derive more information about the number of capillaries or the oxidative potential of muscle fiber types. Simultaneous visualization of multiple fiber types in a single merged image enables economical use of muscle samples and provides simple and rapid identification of all fiber types that are present in rat limb muscles.
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Affiliation(s)
- Samo Ribarič
- Institute of Pathophysiology, Medical Faculty, University of Ljubljana, SI-1000 Ljubljana, Slovenia
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Abstract
Detection of multiple antigens in the same tissue section can be done by combining a range of immunohisto/cytochemical techniques based either on light microscopic chromogenic precipitates or fluorochrome labeling. Light microscopic techniques preferred for this purpose use combinations of immunogold silver staining (black precipitate), immunoperoxidase, immunoalkaline phosphatase and immunogalactosidase methods using chromogens of different colors. Fluorochrome labels favored for these combinations include AMCA (blue), FITC (green), rhodamine (orange-red) and Cy5 (far red), their matching synthetic members from the Alexa series, or quantum dots. Antibodies directly labeled or those from noncross-reacting animal species (e.g., mouse, rabbit, goat, guinea pig etc.) can be applied simultaneously. When the antigens of interest are in separate cells or cell compartments (e.g., in cell membrane, cytoplasm or nucleus), and only cross-reacting antibodies are available, there have also been ways of avoiding unwanted cross-talk. These include the exploitation of the shielding effect of chromogens; inactivation of immuno-sequences of the first staining by using either acidic elution, formaldehyde fixation or microwave heating; combining unlabeled and hapten-labeled antibodies; or using labeled monovalent F(ab) secondary antibodies. In this chapter we briefly discuss the principle of multiple antigen immunolabeling and provide useful protocols for its performance.
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Robertson D, Savage K, Reis-Filho JS, Isacke CM. Multiple immunofluorescence labelling of formalin-fixed paraffin-embedded (FFPE) tissue. BMC Cell Biol 2008; 9:13. [PMID: 18366689 PMCID: PMC2288605 DOI: 10.1186/1471-2121-9-13] [Citation(s) in RCA: 152] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2007] [Accepted: 03/19/2008] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Investigating the expression of candidate genes in tissue samples usually involves either immunohistochemical labelling of formalin-fixed paraffin-embedded (FFPE) sections or immunofluorescence labelling of cryosections. Although both of these methods provide essential data, both have important limitations as research tools. Consequently, there is a demand in the research community to be able to perform routine, high quality immunofluorescence labelling of FFPE tissues. RESULTS We present here a robust optimised method for high resolution immunofluorescence labelling of FFPE tissues, which involves the combination of antigen retrieval, indirect immunofluorescence and confocal laser scanning microscopy. We demonstrate the utility of this method with examples of immunofluorescence labelling of human kidney, human breast and a tissue microarray of invasive human breast cancers. Finally, we demonstrate that stained slides can be stored in the short term at 4 degrees C or in the longer term at -20 degrees C prior to images being collected. This approach has the potential to unlock a large in vivo database for immunofluorescence investigations and has the major advantages over immunohistochemistry in that it provides higher resolution imaging of antigen localization and the ability to label multiple antigens simultaneously. CONCLUSION This method provides a link between the cell biology and pathology communities. For the cell biologist, it will enable them to utilise the vast archive of pathology specimens to advance their in vitro data into in vivo samples, in particular archival material and tissue microarrays. For the pathologist, it will enable them to utilise multiple antibodies on a single section to characterise particular cell populations or to test multiple biomarkers in limited samples and define with greater accuracy cellular heterogeneity in tissue samples.
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Affiliation(s)
- David Robertson
- Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK.
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Ferri GL, Spiga G, Brancia C, D'Amato F, Saderi N, Noli B, Cocco C. Multiple immunofluorescence technology. Appl Immunohistochem Mol Morphol 2006; 14:454-5. [PMID: 17122645 DOI: 10.1097/01.pai.0000213142.24407.09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Brown JK, Pemberton AD, Wright SH, Miller HRP. Primary antibody-Fab fragment complexes: a flexible alternative to traditional direct and indirect immunolabeling techniques. J Histochem Cytochem 2004; 52:1219-30. [PMID: 15314089 DOI: 10.1369/jhc.3a6200.2004] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Immunolabeling with immune complexes of primary and secondary antibodies offers an attractive method for detecting and quantifying specific antigen. Primary antibodies maintain their affinity for specific antigen after labeling with Fab fragments in vitro. Incubation of these immune complexes with excess normal serum from the same species as the primary antibody prevents free Fab fragments from recognizing immunoglobulin. Effectively a hybrid between traditional direct and indirect immunolabeling techniques, this simple technique allows primary antibodies to be non-covalently labeled with a variety of reporter molecules as and when required. Using complexes containing Fab fragments that recognize both the Fc and F(ab')2 regions of IgG, we show that this approach prevents nonspecific labeling of endogenous immunoglobulin, can be used to simultaneously detect multiple antigens with primary antibodies derived from the same species, and allows the same polyclonal antibody to be used for both antigen capture and detection in ELISA.
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Affiliation(s)
- Jeremy K Brown
- Department of Veterinary Clinical Studies, University of Edinburgh, Easter Bush Veterinary Centre, Midlothian EH25 9RG, UK.
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Cocco C, Melis GV, Ferri GL. Embedding media for cryomicrotomy: an applicative reappraisal. Appl Immunohistochem Mol Morphol 2003; 11:274-80. [PMID: 12966356 DOI: 10.1097/00129039-200309000-00012] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We reassess here the formulation of cryoembedding media in connection with recent developments in commercial cryomicrotomes. Water-based solutions of polyvinyl alcohols were our starting media, and each of 2 different polymers (56-98, MW approximately 195000; and 6-98, MW approximately 47000) showed a critical concentration for optimum sectioning. At higher or lower polymer concentrations, wrinkles and folds became apparent in tissue areas of sections, or in the sectioned embedding medium areas between tissues, respectively. Addition of polyethylene glycol (MW 380-420) further facilitated and improved sectioning, resulting in frozen tissue blocks that cut well in the 2 to 100 microm range and further, using disposable blades throughout. Applying a wide temperature differential between tissue specimen (-11 degrees C to -13 degrees C) and cutting knife (-33 degrees C to -35 degrees C), serial adjacent sections were reproducibly obtained at a 2-microm setting, singly or in short ribbons. Embedding media of low and high viscosity were obtained, depending on the polyvinyl alcohol polymer used, and could be applied sequentially for tissue infiltration followed by embedding with precise sample orientation. When required, media were made semisolid by addition of carboxymethylcellulose.
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Affiliation(s)
- Cristina Cocco
- NEF-Laboratory,Department of Cytomorphology, University of Cagliari at Monserrato, Cagliari, Italy
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Affiliation(s)
- Nicolas Demaurex
- Department of Physiology, University of Geneva Medical Center, CH-1211, Geneva 4, Switzerland
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Brouns I, Van Nassauw L, Van Genechten J, Majewski M, Scheuermann DW, Timmermans JP, Adriaensen D. Triple immunofluorescence staining with antibodies raised in the same species to study the complex innervation pattern of intrapulmonary chemoreceptors. J Histochem Cytochem 2002; 50:575-82. [PMID: 11897811 DOI: 10.1177/002215540205000415] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A general problem in immunocytochemistry is the development of a reliable multiple immunolabeling method when primary antibodies must be used that originate in the same species. We have developed a protocol for the immunodetection of three antigens in a single tissue preparation, using unconjugated primary antibodies raised in the same species. Immunocytochemical detection of neuronal nitric oxide synthase, calcitonin gene-related peptide, and calbindin D28k in the lung of rats demonstrated that part of the pulmonary neuroepithelial bodies are selectively contacted by at least three different nerve fiber populations. The first antigen was detected using tyramide signal amplification, a very sensitive method allowing a dilution of the first primary antibody far beyond the detection limit of fluorescently labeled secondary antibodies. The second antigen was visualized by a fluorophore-conjugated secondary monovalent Fab antibody that at the same time blocks the access of the third secondary antibody to the second primary antibody. Moreover, the monovalence of the Fab fragment prevents the third primary antibody from binding with the second-step secondary antibody. The triple staining technique described here is generally applicable, uses commercially available products only, and allows the detection of three antigens in the same preparation with primary antibodies that are raised in the same species.
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Affiliation(s)
- Inge Brouns
- Laboratory of Cell Biology and Histology, University of Antwerp (RUCA), Groenenborgerlaan 171, B-2020 Antwerp, Belgium
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Ferri GL, Isola J, Berger P, Giro G. Direct eye visualization of Cy5 fluorescence for immunocytochemistry and in situ hybridization. J Histochem Cytochem 2000; 48:437-44. [PMID: 10681398 DOI: 10.1177/002215540004800314] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Cyanine 5.18 (or Cy5) is a fluorochrome emitting in the long-red/far-red range, usually regarded as unsuitable for direct observation by the human eye. We describe here the optimization of a direct visualization approach to Cy5 labeling, based on a standard fluorescence microscope with mercury light excitation and applicable to both immunocytochemistry and fluorescent in situ hybridization. Crucial factors were (a) an excitation path in the microscope not absorbing light in the orange-red range, up to 640 nm, (b) a 588-640-nm excitation filter range, distinctly below the excitation optimum for Cy5, (c) a 650-700-nm emission filter range, transmitting the low-wavelength portion of Cy5 emission, and (d) high-efficiency filter set components allowing a narrow gap between excitation and emission ranges without visible cross-talk of excitation light in the emission path.
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Affiliation(s)
- G L Ferri
- Neuro-&-Endocrine Research, Department of Cytomorphology, University of Cagliari and Oasi IRCCS, Troina, Italy
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Possenti R, Rinaldi AM, Ferri GL, Borboni P, Trani E, Levi A. Expression, processing, and secretion of the neuroendocrine VGF peptides by INS-1 cells. Endocrinology 1999; 140:3727-35. [PMID: 10433233 DOI: 10.1210/endo.140.8.6920] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The neurotropin-inducible gene vgf is expressed in neuronal and endocrine tissues. It encodes a secretory protein that is proteolytically processed in neuronal cells to low molecular mass polypeptides. In the present report, we show that vgf is expressed in different insulinoma cell lines and in normal rat pancreatic islets. In the insulinoma-derived beta-cell line INS-1, vgf messenger RNA was transcriptionally up-regulated by increased levels ofintracellular cAMP, but not by the addition of glucose (20 mM) or phorbol 12-myristate 13-acetate (100 nM). Furthermore, nerve growth factor failed to stimulate vgf gene expression. In INS-1 cells, the VGF protein was shown to be processed in a post endoplasmic reticulum compartment to produce a peptide profile similar to that seen in neurons. The release of such VGF peptides occurred at a low rate in the absence of secretory stimuli (<2%/h). A 3-fold increase in the rate of release was seen after the addition of glucose (15 mM), a 4-fold increase was seen after (Bu)2cAMP (1 mM), and a 6-fold increase was seen after phorbol 12-myristate 13-acetate (100 nM). These results indicated that insulin-containing cells produce VGF-derived peptides that are released via a regulated pathway in response to insulin secretagogues.
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Affiliation(s)
- R Possenti
- Department of Neuroscience, University of Tor Vergata, Rome, Italy.
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Multiple Biotin-Avidin Amplification for Multiple Immunostaining. Appl Immunohistochem Mol Morphol 1999. [DOI: 10.1097/00129039-199903000-00015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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