1、Western Blot 常见检测方法 化学化学显显色法色法 如如DAB显显色色 放射自放射自显显影法影法 如同位素如同位素 化学化学发发光法光法 如如 ECL 化学化学荧荧光法光法 如如IRdye680、 、IRdye780 化学化学显显色法操作色法操作简简便,无需暗房和便,无需暗房和显显影影设备设备, ,显显色直色直观观,但灵敏度,但灵敏度较较低,国外已不常低,国外已不常见见。 。化学化学发发光法(光法(ECL)比化学)比化学显显色法灵敏度高,可达色法灵敏度高,可达pg水水平。但由于是平。但由于是酶酶促反促反应应,不同曝光,不同曝光时间时间得到的信号与得到的信号与样样品量不成品量不成线线性
2、关系性关系 ,不能做准确定量。,不能做准确定量。荧荧光法采用光法采用荧荧光光检测检测原理,操作原理,操作简单简单, ,荧荧光信号光信号强强弱弱直接反映目的蛋白量,可直接反映目的蛋白量,可进进行精确定量;行精确定量;还还可以根据可以根据荧荧光染料的不同,用不同的光染料的不同,用不同的荧荧光二抗可以在同一光二抗可以在同一张张膜上同膜上同时检测时检测两种蛋白两种蛋白质质。 。不同检测方法特点ECL常见问题 暗房操作麻暗房操作麻烦烦,曝光,曝光时间难时间难以控制,无法准确定量以控制,无法准确定量 背景高,高背景高,高浓浓度蛋白易出度蛋白易出现现“ “吹泡吹泡” ”现现象象 检测检测两种蛋白两种蛋白时时
3、,需要,需要Stripping和和Re-probe,操,操作复作复杂杂 胶片上无法直接胶片上无法直接观观察到察到Marker解决方案:Odyssey 双色红外荧光成像系统 荧光 红外 双色 荧光准确定量、线性范围宽广 红外背景低、信噪比高 双色同时检测、同时输出Odyssey VS ECL流程ECLOdyssey1跑胶跑胶2转膜转膜3封闭封闭4结合一抗、洗涤结合一抗、洗涤5结合酶标记二抗、洗涤结合红外染料标记二抗、洗涤,成像6发光试剂盒7暗房曝光成像Antigen on membranePrimary antibody binds to antigenIRDye labeled seconda
4、ry antibody binds to primary antibody 荧光直接检测INFRAREDLASER DIODEINFRARED APD DETECTORON-SCREEN Display信号持久信号持久 不需要底物不需要底物 不需要底片不需要底片/暗室暗室 TIMETIMECHEMILUMINESCENCE 动态信号信号随时间变化 信号不与目标蛋白浓度成比例关系ODYSSEY 静态信号信号不随时间变化 信号和目标蛋白浓度成比例关系High concentration / signalMedium concentration / signalLow concentration /
5、 signalSaturationBackground0,00,0INTENSITY红外荧光 VS 化学发光定量线性范围定量线性范围Odyssey能检测到0.6pg的蛋白(灵敏度高)Odyssey成像呈现一个很好的线性(定量准确)ECLODYSSEYOdyssey系统定量的线性相关性 倍比稀释的倍比稀释的 IRDye 800-标记的抗体标记的抗体. R2 从从1.5 ng to 0.8 pg 是是 0.99996, 极佳的线性相关性。极佳的线性相关性。1.5 ng0.8 pg极佳的线性相关性增加了定量的准确性Dilutions of transferrin detected with rabb
6、it anti-Tf primary and Alexa Fluor 680 goat anti-rabbit secondary. Sensitivity is 250-fold higher than reported for the Bio-Rad Molecular Imager FX with fluorescent antibodies, 100-fold higher than ECL (BioTechniques 29:636-642).红外荧光红外荧光 VS 化学发光化学发光红外荧光 VS 化学发光成像效果成像效果Odyssey曝光秒曝光秒曝光分钟曝光分钟曝光分钟曝光分钟曝光
7、分钟曝光分钟红外红外+ +荧光荧光 DEMO实验步骤Odyssey:膜+一抗孵育+荧光标记抗体孵育+Odyssey扫描成像ECL:膜+一抗孵育+酶联二抗孵育+底物显色+ UVP扫描成像实验目的 检测培养细胞转染外源基因的表达状况Marker S1 S2 S3 S4Marker S1 S2 S3 S4Odyssey结果 ECL结果 信号强度 51 20 10 4信号强度 302 62 30 19(Odyssey软件分析结果) 结论Odyssey和ECL的相对灵敏度相差不大Odyssey红外激光成像系统具有更好的线性关系和更精确的定量结果 Odyssey扫描图能同时看到Marker 和目标蛋白,E
8、CL看不到 Marker10:4:2:1 稀释 红外技术优点红外技术优点低背景低背景NIR DyesBiomoleculesPorphyrinsVisible FluorophoresPAHs1000 nm800600400200All othersequencers400-650 nmLI-COR700 - 800 nm红外荧光 vs 可见荧光膜背景信号膜背景信号 背景更低,信噪比高,保证更好检测灵敏度 定量线性范围更宽,可达4个数量级,定量更准确 穿透力更强(活体成像的应用)红外荧光优点Odyssey双色同时检测800 nm700 nmOverlay两套独立激发检测系统700通道:680n
9、m激发 720nm检测800通道:780nm激发 820nm检测No need to strip!No need to re-probe!Target proteinAnti-rabbit 800 channelNormalizer targetAnti-mouse 700 channel* Two-color detection requires primary antibodies from different hosts双色ERK蛋白的磷酸化Anti-EGFR and anti-phospho-EGFR antibody specificity in A431 cellsSingle c
10、olor images (B and C) can be overlaid (A) to show both total protein and phosphorylated protein.The mobility shift caused by phosphorylation is visible (A) as indicated by the red bands above the yellow bands. (yellow indicates overlapping red and green signals).双色EMSABinding of T7 RNAP to two DNA f
11、ragments containing the T7 promoter sequence, labeled with either IRDye 700 (red) or IRDye 800 (green).700 and 800 Overlay700 nm Channel800 nm ChannelDNA-Protein ComplexUnbound DNA IRDye 800Unbound DNA IRDye 700Odyssey双色检测的优越性双色输出,两个目标基因同时检测,减少了工作量,而且杂交条件均等,便于两个数据的对比杂交结果对比输出,结论更加直观,一目了然可进行准确的量化分析The
12、 Odyssey In-Cell Western (ICW) Assay is a high-throughput approach to simultaneously detect and quantify two separate proteins directly within cells.细胞培养 Culture cells to confluency in 96-well or 384-well plates处理细胞 Treat cells (inhibitor, stimulator, etc)固定细胞 Fix cells (3.7%formaldehyde, methanol o
13、r Prefer)透化细胞 Permeabilize cells (0.1%Triton-X 100)Incubate with IRDye secondary antibodies(e.g.: IRDye 680 and IRDye 800CW)Incubate with 2 primary antibodiesIncubate with 1 primary antibodyIncubate with IRDye secondary antibody anda DNA stain (e.g.: To-Pro-3)Odyssey系统扫描 Scan plate directly and anal
14、yze on the LI-COR Infrared Imaging Systems.In-Cell Western 工作流程Membrane Westerns vs ICWEGF对ERK磷酸化水平的调控700 nm (Total ERK) 800 nm (Phospho-ERK)Composite Image OverlayEGF Concentration-02004006008001000120014001600180000.20.40.81.63.126.2512.52550100% Induction of ERKPhosphorylationConcentration EGF (n
15、g/ml)A431 cells stimulated with serial dilutions of EGF to optimize activation of ERK1/2. Phospho-ERK signal was normalized using total ERK signal.EGF抑制剂对ERK磷酸化水平的影响Quantitative and simultaneous measurements of total ERK and phosphorylation of ERK in response to EGF in the presence of EGFR inhibitor
16、. m nmInhibitor - - 3 1.5 750 375 180 90 45 22 11 5.5EGF - + + + + + + + + + + +700/800 nm 800 nm (Total ERK) 700 nm phosphorylated ERK In-Cell Western 软件模块在用客户提供的结果图片由上海中医药大学复杂系统研究中心Dr Liu提供。Odyssey ICW 的优点高速高速 与普通膜杂交相比,通量提高30倍 ICW 软件提供便捷的计算和分析准确准确 红外检测提供最准确的量化结果。 避免在细胞裂解等步骤中蛋白的损失。操作操作简单简单 操作步骤简单IC
17、W相关试剂 目前可以提供4种试剂盒其他经ICW验证的抗体以及kit 应用文献一PPP PEGFRRasRafMekERKJAKSTAT1STAT3Grb2SOSEGFEGFR SignalingRAS/RAF/Mek/ERK信号通路KSR1左图:The effect of KSR1 phosphorylation on MEK1/2 and RSK1 activation. 上上图图: :Mutation of KSR1 phosphorylation sites enhances the duration of ERK activation.应用文献二蛋白质芯片扫描 CST PathScan
18、 RTK Signaling antibody array kit(7949) kit包括:所有的辅助产品和试剂 R&D 4种适合Licor检测试剂盒 小动物活体成像-双色小动物活体成像-附件软件功能 仪器软件 Administration Diagnostics 应用软件 图象控制 背景扣除 条带发现和定位 定量 ICW % 结果计算(including normalization) 小动物活体分析Odyssey系统发表文献统计Paper ListNagashima, K., et al. Genetic and pharmacological inhibition of PDK1 in c
19、ancer cells characterization of a selective allosteric kinase inhibitor J. Biol. Chem 286:6433 (2011)Sneeringer, C.J., et al. Coordinated activities of wild-type plus mutant EZH2 drive tumor-associated hypertrimethylation of lysine 27 on histone H3 (H3K27) in human B-cell lymphomas PNAS 107:20980 (2
20、010)Cittelly, D. M., et al. Oncogenic HER2D16 suppresses miR-15a/16 and deregulates BCL-2 to promote endocrine resistance of breast tumors Carcinogenesis 31:2049 (2010)Pan, Y. et al. Sprouty2-modulated Kras signaling rescues Shp2 deficiency during lens and lacrimal glad development. Development 137,
21、 1085-1093 (2010)Markovic, D et al. Intracellular mechanisms regulating corticotropin-releasing hormone receptor-2beta endocytosis and interaction with extracellularly regulated kinase 1/2 and p38 mitogen-activated protein kinase signaling cascades. Mol Endocrinol. 22(3): 689-706 (2008)总 结准确定量提供更完善的数据,提升文章档次成像效果好背景低,条带清晰,没有吹泡现象双色检测靶蛋白+总蛋白+Maker 同时检测成本低无需底物,无需胶片,无需暗室,二抗稀释倍数高扩展应用ICW,小动物活体成像等Odyssey 系统概况 全球装机超过5,000 systems,国内近300套系统 9,590 publications