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Li Y, Thompson H, Hemphill C, Hong F, Forrester J, Johnson RH, Zhang W, Meldrum DR. An improved one-tube RT-PCR protocol for analyzing single-cell gene expression in individual mammalian cells. Anal Bioanal Chem 2010; 397:1853-9. [PMID: 20490471 DOI: 10.1007/s00216-010-3754-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 04/07/2010] [Accepted: 04/13/2010] [Indexed: 10/19/2022]
Abstract
It is well known that gene expression is regulated at the level of individual cells, and more evidence is now emerging that heterogeneity of cell regulation is orders of magnitude greater than previously thought. In order to detect meaningful variations in transcription levels, it is necessary to measure gene expression at single cell levels rather than in bulk cells, where individual differences or heterogeneity could be lost. In this work, we report an improved reverse-transcriptase polymerase chain reaction (RT-PCR) protocol which allows the direct measurement of gene expression in one tube (5-25 microl of total PCR mixture) at the single mammalian cell level. The protocol employs a new cell lysis buffer, and involves no RNA isolation or nested PCR steps, significantly reducing the possibility of contamination and errors. We successfully applied this protocol in qRT-PCR and linear-after-the-exponential (LATE)-PCR to analyze selected genes of various expression levels from three cell lines. Although further characterization of RNA stability is important, the preliminary results showed that gene expression heterogeneity could be common among members of genetically identical cell populations. The protocol illustrated can be utilized for a wide array of applications without much modification, such as cancer cell analysis and preimplantation genetic diagnostics. In addition, the protocol is based on intercalator-based (SYBR Green PCR) chemistry, which is less expensive and suitable for high-throughput platforms.
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Affiliation(s)
- Yongzhong Li
- Center for Ecogenomics, The Biodesign Institute, Arizona State University, P.O. Box 876501, Tempe, AZ 85287-6501, USA.
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Tanaka A, Harikai N, Saito S, Yakabe T, Funaoka S, Yokoyama K, Fujiwara K, Iwao-Koizumi K, Murata S, Kinoshita K. All-in-one tube method for quantitative gene expression analysis in oligo-dT(30) immobilized PCR tube coated with MPC polymer. ANAL SCI 2009; 25:109-14. [PMID: 19139583 DOI: 10.2116/analsci.25.109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In this report, we have developed a novel quantitative RT-PCR protocol in which the procedure including mRNA purification can be performed in an all-in-one tube. To simplify gene expression analysis, oligo-dT(30) immobilized PCR tubes were used serially to capture mRNA, synthesize solid-phase cDNA, and amplify specific genes. The immobilized oligo-dT(30) can efficiently capture mRNA directly from crude human cell lysates. The captured mRNA is then amplified by one-step reverse transcription PCR (RT-PCR) with initial cDNA synthesis followed by PCR. In RT-PCR, this new reusable PCR tube device can be employed for multiple PCR amplifications with different primer sets from a solid-phase oligo-dT(30) primed cDNA library. This paper introduces a novel and highly reliable all-in-one tube method for rapid cell lysis, followed by quantitative preparation and expression analysis of target mRNA molecules with small amounts of sample. This procedure allows all steps to be carried out by sequential dilution in a single tube, without chemical extraction. We demonstrate the utility of this novel method by quantification of two housekeeping genes, beta-actin and GAPDH, in HeLa cells. We believe this new PCR device can be useful as a platform for various mRNA expression analyses, including basic research, drug screening, and molecular toxicology, as well as for molecular pathological diagnostics.
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Affiliation(s)
- Atsuko Tanaka
- School of Pharmaceutical Sciences, Mukogawa Women's University, Koshien, Nishinomiya 663-8179, Japan
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Bengtsson M, Hemberg M, Rorsman P, Ståhlberg A. Quantification of mRNA in single cells and modelling of RT-qPCR induced noise. BMC Mol Biol 2008; 9:63. [PMID: 18631407 PMCID: PMC2483285 DOI: 10.1186/1471-2199-9-63] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Accepted: 07/17/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Gene expression has a strong stochastic element resulting in highly variable mRNA levels between individual cells, even in a seemingly homogeneous cell population. Access to fundamental information about cellular mechanisms, such as correlated gene expression, motivates measurements of multiple genes in individual cells. Quantitative reverse transcription PCR (RT-qPCR) is the most accessible method which provides sufficiently accurate measurements of mRNA in single cells. RESULTS Low concentration of guanidine thiocyanate was used to fully lyse single pancreatic beta-cells followed by RT-qPCR without the need for purification. The accuracy of the measurements was determined by a quantitative noise-model of the reverse transcription and PCR. The noise is insignificant for initial copy numbers >100 while at lower copy numbers the noise intrinsic of the PCR increases sharply, eventually obscuring quantitative measurements. Importantly, the model allows us to determine the RT efficiency without using artificial RNA as a standard. The experimental setup was applied on single endocrine cells, where the technical and biological noise levels were determined. CONCLUSION Noise in single-cell RT-qPCR is insignificant compared to biological cell-to-cell variation in mRNA levels for medium and high abundance transcripts. To minimize the technical noise in single-cell RT-qPCR, the mRNA should be analyzed with a single RT reaction, and a single qPCR reaction per gene.
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Affiliation(s)
- Martin Bengtsson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, The Churchill Hospital, Oxford, OX3 7LJ, UK
- Department of Clinical Sciences, Lund University, Clinical Research Centre, 205 02 Malmö, Sweden
| | - Martin Hemberg
- Department of Bioengineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
- Department of Ophthalmology and Program in Neurobiology, Children's Hospital Boston, Harvard Medical School, 1 Blackfan Circle, Boston, MA 02115, USA
| | - Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, The Churchill Hospital, Oxford, OX3 7LJ, UK
| | - Anders Ståhlberg
- Stem Cell Center, Lund University, BMC B10, 221 84 Lund, Sweden
- Department of Clinical Neuroscience and Rehabilitation, Institute of Neurosciences and Physiology, Sahlgrenska Academy at Göteborg University, Medicinaregatan 9A, 413 90 Göteborg, Sweden
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Herrington J, Sanchez M, Wunderler D, Yan L, Bugianesi RM, Dick IE, Clark SA, Brochu RM, Priest BT, Kohler MG, McManus OB. Biophysical and pharmacological properties of the voltage-gated potassium current of human pancreatic beta-cells. J Physiol 2005; 567:159-75. [PMID: 15932888 PMCID: PMC1474166 DOI: 10.1113/jphysiol.2005.089375] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Voltage-gated potassium (Kv) currents of human pancreatic islet cells were studied by whole-cell patch clamp recording. On average, 75% of the cells tested were identified as beta-cells by single cell, post-recording RT-PCR for insulin mRNA. In most cells, the dominant Kv current was a delayed rectifier. The delayed rectifier activated at potentials above -20 mV and had a V(1/2) for activation of -5.3 mV. Onset of inactivation was slow for a major component (tau = 3.2 s at +20 mV) observed in all cells; a smaller component (tau = 0.30 s) with an amplitude of approximately 25% was seen in some cells. Recovery from inactivation had a tau of 2.5 s at -80 mV and steady-state inactivation had a V(1/2) of -39 mV. In 12% of cells (21/182) a low-threshold, transient Kv current (A-current) was present. The A-current activated at membrane potentials above -40 mV, inactivated with a time constant of 18.5 ms at -20 mV, and had a V(1/2) for steady-state inactivation of -52 mV. TEA inhibited total Kv current with an IC50 = 0.54 mm and PAC, a disubstituted cyclohexyl Kv channel inhibitor, inhibited with an IC50 = 0.57 microm. The total Kv current was insensitive to margatoxin (100 nm), agitoxin-2 (50 nm), kaliotoxin (50 nm) and ShK (50 nm). Hanatoxin (100 nm) inhibited total Kv current by 65% at +20 mV. Taken together, these data provide evidence of at least two distinct types of Kv channels in human pancreatic beta-cells and suggest that more than one type of Kv channel may be involved in the regulation of glucose-dependent insulin secretion.
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Affiliation(s)
- James Herrington
- Department of Ion Channels, Merck Research Laboratories, PO Box 2000, RY-80N-C31, Rahway, NJ 07065, USA.
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Hartshorn C, Anshelevich A, Wangh LJ. Rapid, single-tube method for quantitative preparation and analysis of RNA and DNA in samples as small as one cell. BMC Biotechnol 2005; 5:2. [PMID: 15649321 PMCID: PMC546192 DOI: 10.1186/1472-6750-5-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2004] [Accepted: 01/13/2005] [Indexed: 12/04/2022] Open
Abstract
Background Current methods for accurate quantification of nucleic acids typically begin with a template preparation step in which DNA and/or RNA are freed of bound proteins and are then purified. Isolation of RNA is particularly challenging because this molecule is sensitive to elevated temperatures and is degraded by RNases, which therefore have to be immediately inactivated upon cell lysis. Many protocols for nucleic acids purification, reverse transcription of RNA and/or amplification of DNA require repeated transfers from tube to tube and other manipulations during which materials may be lost. Results This paper introduces a novel and highly reliable single-tube method for rapid cell lysis, followed by quantitative preparation and analysis of both RNA and/or DNA molecules in small samples. In contrast to previous approaches, this procedure allows all steps to be carried out by sequential dilution in a single tube, without chemical extraction or binding to a matrix. We demonstrate the utility of this method by quantification of four genes, Xist, Sry and the two heat-inducible hsp70i (hsp70.1 and hsp70.3), as well as their RNA transcripts in single mouse embryos and in isolated blastomeres. Conclusion This method virtually eliminates losses of nucleic acids and is sensitive and accurate down to single molecules.
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Affiliation(s)
| | - Aleksandra Anshelevich
- Department of Biology, Brandeis University, Waltham MA 02454-9110, USA
- Current address: Division of Cardiology, Beth Israel Medical Center, Harvard Institutes of Medicine, Boston, MA 02115, USA
| | - Lawrence J Wangh
- Department of Biology, Brandeis University, Waltham MA 02454-9110, USA
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Tanaka Y, Koido S, Xia J, Ohana M, Liu C, Cote GM, Sawyer DB, Calderwood S, Gong J. Development of Antigen-Specific CD8+CTL in MHC Class I-Deficient Mice through CD4 to CD8 Conversion. THE JOURNAL OF IMMUNOLOGY 2004; 172:7848-58. [PMID: 15187169 DOI: 10.4049/jimmunol.172.12.7848] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD8+ CTL are the predominant tumoricidal effector cells. We find, however, that MHC class I-deficient mice depleted of CD8+ T cells are able to mount an effective antitumor immunity after immunization with fused dendritic/tumor cells. Such immunity appears to be mediated by the generation of phenotypic and functional CD8+ CTL through CD4+ to CD8+ conversion, which we have demonstrated at the single cell level. CD4+ to CD8+ conversion depends on effective in vivo activation and is promoted by CD4+ T cell proliferation. The effectiveness of this process is shown by the generation of antitumor immunity through adoptive transfer of primed CD4 T cells to provide protection against tumor cell challenge and to eliminate established pulmonary metastases.
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Affiliation(s)
- Yasuhiro Tanaka
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
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