- Description
- Additional Information
- Readable Documents
- Assay Principle
- Reviews
Key Benefits
- Safe – Non Radioactive Enzyme release assay.
- Versatile – Useful for measuring activity of T Cells, Primary Cells, NK, complement and other lytic agents.
- Assay can be run in serum supplemented media.
- Homogenous – One-step, no wash assay. Assay can be run in same plate as samples.
- FAST – Results in 3-5 minutes. Chromium 51 or europium release for measurement are time consuming. The inherent sensitivity of luciferase detection is enhanced by the amplification effect of enzyme turnover, which produces thousands, millions or billions of high – energy molecules for each molecule of the enzyme.
- Highly Sensitive – Can detect fewer than 500 cells/well in the presence of serum or as few as 10 cells/well in serum-free or heat-killed media.
- GAPDH: The fact that GAPDH is a natural component of cells, and does not need to be introduced into the cells in any manner, distinguishes this assay from all methods which require prelabelling of cells, transfection, transformation, or other methods of introducing proteins or other molecules into the target cells in order to generate a signal in a later step.
- Advantages for measurement of cell mediated or complement mediated cytolysis – It is usually desirable to use smaller numbers of TCells than are needed for the 51Cr – release assay, since excessive numbers of effector cells can increase the background signal. This is now possible due to the high sensitivity of aCella-Tox.
- ADCC / CMC Assays – A non radioactive alternative to 51Cr assays. Please click here for a direct comparison between the aCella-TOX and (51Cr) Chromium Release Methods
- HTS – Adaptable for High Throughput format
- Non-destructive assay allows monitoring of additional parameters.
Additional information
| Kit Size | 500, 1000 |
|---|---|
| Includes | No Plates, 5 Lumi Plates, 5 Lumi Plates + 5 Tissue Culture Plates |
GAPDH is an important enzyme in the glycolysis and gluconeogenesis pathways. This homotetrameric enzyme catalyzes the oxidative phosphorylation of D-glyceraldehyde-3-phosphate to 1,3-diphosphoglycerate in the presence of cofactor and inorganic phosphate. In the aCella-TOX reaction scheme the release of GAPDH is coupled to the activity of the enzyme 3-Phosphoglyceric Phosphokinase (PGK) to produce ATP. ATP is detected via the luciferase, luciferin Bioluminescence methodology. Further, aCella-TOX is a homogeneous cytotoxicity assay; alternatively in dual mode, aCella-TOX can measure cytotoxicity and cell viability in the same plate. Culture supernatants can also be removed from the original plate and assayed in a different plate, allowing kinetics runs to be set up. The assay is non-destructive, allowing the monitoring of additional parameters such as gene expression.
| Document Title |
| aCella-TOX v1_3 Protocol |
| aCella-TOX Datasheet |
| msds.aCella-TOX |
| Title | File | Link | Author(s) | Journal | Year; Edition:Pages |
| Heat shock enhances the expression of cytotoxic granule proteins and augments the activities of tumor-associated antigen-specific cytotoxic T lymphocytes. | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3468674/ | Takahashi A, Torigoe T, Tamura Y, et al. | Cell Stress & Chaperones | 2012;17(6):757-763 | |
| IGF-1R peptide vaccines/mimics inhibit the growth of BxPC3 and JIMT-1 cancer cells and exhibit synergistic antitumor effects with HER-1 and HER-2 peptides. | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4368154/ | Foy KC, Miller MJ, Overholser J, Donnelly SM, Nahta R, Kaumaya PT | Oncoimmunology | 2014;3(11):e956005 | |
| HER-3 peptide vaccines/mimics: Combined therapy with IGF-1R, HER-2, and HER-1 peptides induces synergistic antitumor effects against breast and pancreatic cancer cells. | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4368151/ | Miller MJ, Foy KC, Overholser JP, Nahta R, Kaumaya PT | Oncoimmunology | 2014;3(11):e956012 | |
| Phase I Active Immunotherapy With Combination of Two Chimeric, Human Epidermal Growth Factor Receptor 2, B-Cell Epitopes Fused to a Promiscuous T-Cell Epitope in Patients With Metastatic and/or Recurrent Solid Tumors. | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2773479/ | Kaumaya PTP, Foy KC, Garrett J, et al. | Journal of Clinical Oncology | 2009;27(31):5270-5277 | |
| Identification of Cellular Proteins Required for Replication of Human Immunodeficiency Virus Type 1. | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3448097/ | Dziuba N, Ferguson MR, O"Brien WA, et al. | AIDS Research and Human Retroviruses | 2012;28(10):1329-1339 | |
| Insulin-Like Growth Factor-1 Receptor Signaling Increases the Invasive Potential of Human Epidermal Growth Factor Receptor 2-Overexpressing Breast Cancer Cells via Src-Focal Adhesion Kinase and Forkhead Box Protein M1. | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4293451/ | Sanabria-Figueroa E, Donnelly SM, Foy KC, et al. | Pharmacology | 2015;87(2):150-161 | |
| Combination Treatment with HER-2 and VEGF Peptide Mimics Induces Potent Anti-tumor and Anti-angiogenic Responses in Vitro and in Vivo. | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3075707/ | Foy KC, Liu Z, Phillips G, Miller M, Kaumaya PTP | The Journal of Biological Chemistry | 2011;286(15):13626-13637 | |
| Resistance to Cytarabine Induces the Up-regulation of NKG2D Ligands and Enhances Natural Killer Cell Lysis of Leukemic Cells. | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2586691/ | Ogbomo H, Michaelis M, Klassert D, Doerr HW, Cinatl J. | Neoplasia (New York, NY) | 2008;10(12):1402-1410 | |
| Anti-Tumor Effects of Peptide Therapeutic and Peptide Vaccine Antibody Co-targeting HER-1 and HER-2 in Esophageal Cancer (EC) and HER-1 and IGF-1R in Triple-Negative Breast Cancer (TNBC). | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4586465/ | Overholser J, Ambegaokar KH, Eze SM, et al. | Disis ML (Nora), ed. Vaccines | 2015;3(3):519-543 | |
| Generation and preclinical characterization of an antibody specific for SEMA4D. | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4966508/ | Fisher TL, Reilly CA, Winter LA, et al. | mAbs | 2016;8(1):150-162 | |
| A Human Anti-M2 Antibody Mediates Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC) and Cytokine Secretion by Resting and Cytokine-Preactivated Natural Killer (NK) Cells. | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4411161/ | Simhadri VR, Dimitrova M, Mariano JL, et al. | Reeves RK, ed. PLoS ONE | 2015;10(4):e0124677 | |
| Natural Cytotoxicity Receptor-Dependent Natural Killer Cytolytic activity Directed at Hepatitis C Virus (HCV) Is Associated With Liver Inflammation, African American Race, IL28B Genotype, and Response to Pegylated Interferon/Ribavirin Therapy in Chronic HCV Infection. | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3997579/ | Meng Q, Rani MRS, Sugalski JM, et al. | The Journal of Infectious Diseases | 2014;209(10):1591-1601 | |
| Myxoma Virus Infection Promotes NK Lysis of Malignant Gliomas In Vitro and In Vivo. | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3677932/ | Ogbomo H, Zemp FJ, Lun X, et al. | Ulasov I, ed. PLoS ONE | 2013;8(6):e66825 | |
| Targeting a Glioblastoma Cancer Stem Cell Population Defined by EGF Receptor Variant III. | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5661963/ | Emlet DR, Gupta P, Holgado-Madruga M, et al. | Cancer research | 2014;74(4):1238-1249 | |
| Genetically Associated CD16+56− Natural Killer Cell Interferon (IFN)-αR Expression Regulates Signaling and Is Implicated in IFN-α-Induced Hepatitis C Virus Decline. | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3295604/ | Conry SJ, Meng Q, Hardy G, et al. | The Journal of Infectious Diseases | 2012;205(7):1131-1141 |
| Reference |
| Methods and compositions for coupled luminescent assays. United States Patent 6,811,990 Corey and Kinders, issued November 2, 2004. |
| Corey, M. J. and Kinders, R. J. (2005) "Coupled Luminescent Methods in Drug Discovery: 3-Min Assays for Cytotoxicity and Phosphatase Activity" Drug Discovery Handbook, Ed. Shayne Cox Gad, published by John Wiley & Sons, Inc., pp. 689-731 |
| Corey, M.J., et al., "A Very Sensitive Coupled Luminescent Assay for Cytoxicity and Complement-Mediated Lysis," Journal of Immunological Methods 207:43-51, 1997. |
| Corey, M. J., et al., Mechanistic Studies of the Effects of Anti-factor H Antibodies on Complement-mediated Lysis,” Journal of Biological Chemistry 275: 12917-12925, 2000. |
| Schafer, H., et al., "A Highly Sensitive Cytotoxicity Assay Based on the Release of Reporter Enzymes, From Stably Transfected Cell Lines," Journal of Immunological Methods 204:89-98, 1997. |
| Racher, LDH Assay, in Cell and tissue culture: Laboratory procedures in biotechnology, A. Doyle and J.B. Griffiths, Eds. 1998, John Wiley & Sons: Chichester, New York, Weinheim. p. 71-5 |
| Decker, T. and Lohmann-Matthes, M.L. (1988) A quick and simple method for the quantitation of lactate dehydrogenase release in measurements of cellular cytotoxicity and tumor necrosis factor (TNF) activity. J. Immunol. Meth. 115, 61-9. |
| Korzeniewski, C. and Callewaert, D.M. (1983) An enzyme-release assay for natural cytotoxicity. J. Immunol. Meth.64, 313-20. |
| Crouch, S.P.M., et al., "The Use of ATP Bioluminescence as a Measure of Cell Proliferation and Cytotoxicity," Journal of Immunological Methods 160:81-88, 1993. |
| Henry Ogbomo, Anke Hahn, Janina Geiler, Martin Michaelis, Hans Wilhelm Doerr, Jindrich Cinatl Jr. NK sensitivity of Neuroblastoma cells determined by a highly sensitive coupled luminescent method;Biochemical and Biophysical Research Comunications 339 (2006) pp375-379. Click here to read the publication |
| Part# | Reagent | Temperature |
| Part # 6001 | 4X Enzyme Assay Reagent | -20C |
| Part # 3008 | 1X Enzyme Assay Diluent | 2-8C |
| Part # 6003 | Glyeraldehyde 3-Phosphate (G3P) | -20C |
| Part # 6002 | 50X Detection Reagent | -20C |
| Part # 3009 | 5.5X Detection Assay Diluent | -20C |
| Part # 3035 | Lytic Agent | 2-8C |
| N/A | 5 Lumi Plates (Catalog# CLATOX100-3L) | N/A |
| N/A | 5 Lumi Plates + 5 Tissue Culture Plates (Catalog# CLATOX100-3P) | N/A |
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做黄单胞,在通过Tn5构建转化子库之后,通过致病力筛选、Tail-PCR获得侧翼序列、比对获得全基因之后,将几个可能与致病力相关的基因做了敲除,现在正在构建互补载体,已经做了敲除转化子的胞外酶活性测定、胞外多糖分泌测定、生长曲线、致病性测定等等,不过不知道将互补做完了之后还有什么可以做的。
目前,来自Streptococcus pyogenes 的CRISPR-Cas9系统应用最为广泛。Cas9 蛋白(含有两个核酸酶结构域,可以分别切割DNA 两条单链。Cas9首先与crRNA及tracrRNA结合成复合物,然后通过PAM序列结合并侵入DNA,形成RNA-DNA复合结构,进而对目的DNA双链进行切割,使DNA双链断裂。
由于PAM序列结构简单(5’-NGG-3’),几乎可以在所有的基因中找 到大量靶点,因此得到广泛的应用。CRISPR-Cas9系统已经成功应用于植物、细菌、酵母、鱼类及哺乳动物细胞,是目前最高效的基因组编辑系统[1]。
通过基因工程手段对crRNA和tracrRNA进行改造,将其连接在一起得到sgRNA(single guide RNA)。融合的RNA具有与野生型RNA类似的活力,但因为结构得到了简化更方便研究者使用。通过将表达sgRNA的原件与表达Cas9的原件相连接,得到可以同时表达两者的质粒,将其转染细胞,便能够对目的基因进行操作[2,3]。
目前常用的CAS9研究方法是通过普通质粒,质粒构建流程如下:
Cas9质粒构建
目前常见的CAS9普通质粒有(汉恒生物提供cas9质粒试剂盒):
虽然普通质粒很多时候也能达到实验效果,但是质粒转染具有效率低,作用时间短暂性等缺点。病毒的出现解决了质粒这些问题,常用的病毒主要有慢病毒和腺病毒,慢病毒常用质粒见addgene(lentiCRISPR v2,lentiGuide-Puro,lentiCas9-Blast),慢病毒可以整合入宿主基因组中,长期稳定的表达(汉恒生物提供CRISPR/cas9 慢病毒包装),但是由于慢病毒克隆能力有限而CAS9本身分子量比较大(大于4kb),且长期插入可能导致乱切,脱靶等,同时慢病毒包装最终获得的滴度不高等原因,腺病毒更有优势,腺病毒克隆能力强,获得的病毒滴度也高。同时相对于普通质粒来说,作用是时间也比较长,可以达到更理想的敲除效果。
缺点:质粒仍然较大,转染难度相对较大。具有碱基识别偏好性,局限了基因编辑的运用范围,而且会导致不同基因位点编辑效率不同。筛选仍然需要较大工作量。
类,其中Ⅰ类和Ⅲ类需要多种CRISPR相关蛋白(Cas蛋白)共同发挥作用,而Ⅱ类系统
只需要一种Cas蛋白即可,这为其能够广泛应用提供了便利条件。
目前,来自Streptococcuspyogenes的CRISPR-Cas9系统应用最为广泛。Cas9蛋白(含
有两个核酸酶结构域,可以分别切割DNA两条单链。Cas9首先与crRNA及tracrRNA结合
成复合物,然后通过PAM序列结合并侵入DNA,形成RNA-DNA复合结构,进而对目的
DNA双链进行切割,使DNA双链断裂。
由于PAM序列结构简单(5’-NGG-3’),几乎可以在所有的基因中找到大量靶点,因此得到广泛的应用。CRISPR-Cas9系统已经成功应用于植物、细菌、酵母、鱼类及哺乳动物细胞,是目前最高效的基因组编辑系统。
http://www.addgene.org/crispr/guide/
一、CRISPR/Cas9系统的构成
CRISPR(clustered,regularly interspaced,short palindromic repeats)是一种来自细菌降解入侵的病毒DNA或其他外源DNA的免疫机制。在细菌及古细菌中,CRISPR系统共分成3类,其中Ⅰ类和Ⅲ类需要多种CRISPR相关蛋白(Cas蛋白)共同发挥作用,而Ⅱ类系统只需要一种Cas蛋白即可,这为其能够广泛应用提供了便利条件。目前,来自Streptococcus pyogenes的CRISPR/Cas9系统应用最为广泛。
Cas9蛋白(含有两个核酸酶结构域,可以分别切割DNA两条单链。Cas9首先与crRNA及tracrRNA结合成复合物,然后通过PAM序列结合并侵入DNA,形成RNA-DNA复合结构,进而对目的DNA双链进行切割,使DNA双链断裂。
研究人员为了将CRISPR/Cas9技术发展为高效的基因打靶工具,又进行了优化和改造。Cong, L.等人[1]在不影响系统效率的情况下,将crRNA和tracrRNA融合为一条RNA。通过这种简化,CRISPR/Cas9系统现仅包括两个元素:Cas9蛋白和sgRNA(single guide RNA)。因此现在人们将CRISPR/Cas9技术也称为Cas9/sgRNA技术。
二、CRISPR/Cas9技术的基因编辑机制
CRISPR/Cas9通过对预设的DNA位点进行切割,造成DNA双链断裂(DSB, double strand break)。这种DNA的损伤可以启动细胞内的修复机制,主要包括两种途径:
一是低保真性的非同源末端连接途径(NHEJ,Non-homologous end joining),此修复机制非常容易发生错误,导致修复后发生碱基的缺失或插入(Indel),从而造成移码突变,最终达到基因敲除的目的。NHEJ是细胞内主要的DNA断裂损伤修复机制。利用靶向核酸酶可以在受精卵水平高效的实现移码突变,从而制备基因敲除模式动物。CRISPR/Cas9技术的出现,使得无需再使用相应物种的ES细胞系就可以制备基因敲除模式生物,且已成功应用于小鼠[5]、大鼠[6]、猪[7]、灵长类[8]、果蝇[9]等等。
第二种DNA断裂修复途径为同源介导的修复(HR, homology-directedrepair),这种基于同源重组的修复机制保真性高,但是发生概率低。在提供外源修复模板的情况下,靶向核酸酶对DNA的切割可以将同源重组发生的概率提高约1000倍[10]。利用这种机制可以实现基因组的精确编辑,如:条件性基因敲除、基因敲进、基因替换、点突变等等。
CRISPR/Cas9技术以自己操作的便捷性,高效的基因编辑能力获得青睐,成为当下科研工作者的新宠儿。各大实验室纷纷加入开发CARISPR/Cas9技术的行列中,媒体也将之评为21世纪最有影响的十大技术之一。让我们跟随CRISPR/Cas9技术的脚步一起加强科研基础的建设,推动生物科研的进步!
详细信息你可以参考:http://www.bbctg.com.cn/show_2/1733.html

