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Tryptone

胰蛋白胨

Company: BD
Catalog#: 211705
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Bacterial Microcolonies in Gel Beads for High-throughput Screening
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Date:
2018-07-05
[Abstract]  High-throughput screening of a DNA library expressed in a bacterial population for identifying potentially rare members displaying a property of interest is a crucial step for success in many experiments such as directed evolution of proteins and synthetic circuits and deep mutational scanning to identify gain- or loss-of-function mutants.

Here, I describe a protocol for high-throughput screening of bacterial (E. coli) microcolonies in gel beads. Single cells are encapsulated into monodisperse water-in-oil emulsion droplets produced with a microfluidic device. The aqueous solution also contains agarose that gelates upon cooling on ice, so that solid gel beads form inside the droplets. During incubation of the emulsion, the cells grow into monoclonal microcolonies ...
[摘要]  在细菌群体中表达的DNA文库的高通量筛选用于鉴定显示感兴趣性质的潜在稀有成员是在许多实验中成功的关键步骤,例如蛋白质和合成回路的定向进化以及用于鉴定增益的深度突变扫描 - 或功能丧失的突变体。

在这里,我描述了一种用于高通量筛选凝胶珠中细菌(大肠杆菌)微菌落的方案。将单细胞包封成用微流体装置产生的单分散油包水乳液液滴。水溶液还含有琼脂糖,其在冰上冷却时凝胶化,从而在液滴内部形成固体凝胶珠。在乳液温育期间,细胞在珠内生长成单克隆微菌落。在从乳液中分离凝胶珠并通过荧光激活细胞分选(FACS)分选后,从凝胶珠中回收细菌,然后准备进行进一步的分选,诱变或分析。为了通过FACS分类,该方案需要荧光读数,例如荧光报告蛋白的表达。测量微小菌落的平均荧光信号降低了高表型细胞间变异性的影响,并且与单细胞分选相比提高了灵敏度。我们应用这种方法在ON和OFF状态下对pBAD启动子文库进行分类(Duarte et al。,2017)。

【背景】荧光激活细胞分选(FACS)具有> 10 7 事件/ h的无与伦比的筛选通量(Davies,2012)。然而,通过FACS根据其荧光分选单个细胞以筛选合成回路的文库(Schaerli和Isalan,2013)经常受到高表型细胞间变异性的阻碍。或者,可以对水凝胶珠中所含的小细胞集落(微集落)进行分类(Weaver ...

In vitro Analysis of Ubiquitin-like Protein Modification in Archaea
Author:
Date:
2018-05-20
[Abstract]  The ubiquitin-like (Ubl) protein is widely distributed in Archaea and involved in many cellular pathways. A well-established method to reconstitute archaeal Ubl protein conjugation in vitro is important to better understand the process of archaeal Ubl protein modification. This protocol describes the in vitro reconstitution of Ubl protein modification and following analysis of this modification in Haloferax volcanii, a halophilic archaeon serving as the model organism. [摘要]  泛素样(Ubl)蛋白广泛分布于古细菌中并参与许多细胞途径。 为了更好地理解古细菌Ub1蛋白质修饰的过程,重建体外古细菌Ubl蛋白质缀合物的完善方法是很重要的。 该协议描述了Ubl蛋白质修饰的体外重建以及在作为模型生物的嗜盐古细菌Haloferax volcanii 中对这种修饰进行分析。

【背景】泛素(Ub)与靶蛋白共价连接的过程被称为泛素化,其控制真核细胞中大量的细胞过程(Glickman和Ciechanover,2002; Komander和Rape,2012)。遍在蛋白化由一系列酶(包括Ub激活酶(E1),Ub结合酶(E2s)和Ub连接酶(E3s))催化。泛素化的体外重建是确定酶之间或E3与蛋白质底物之间特异性的有用测定法(Zhao等人,2012)。在古细菌中,Ubl蛋白SAMP采用Ub折叠,并且与E1样酶UbaA催化的蛋白靶标异肽连接[Maupin-Furlow,(2014)综述]。尽管E1同系物在古细菌中广泛存在,但基于一级序列比较,在大多数古细菌中未预测经典E2或E3酶。我们最近对Haloferax volcanii的研究表明甲硫氨酸亚砜还原酶A(MsrA)是Ubl蛋白质修饰(sampylation)与UbaA一起在体内温和的氧化条件下和< (体外)(fu="">

Quantification of Bacterial Twitching Motility in Dense Colonies Using Transmitted Light Microscopy and Computational Image Analysis
Author:
Date:
2018-04-20
[Abstract]  A method was developed to allow the quantification and mapping of relative bacterial twitching motility in dense samples, where tracking of individual bacteria was not feasible. In this approach, movies of bacterial films were acquired using differential interference contrast microscopy (DIC), and bacterial motility was then indirectly quantified by the degree to which the bacteria modulated the intensity of light in the field-of-view over time. This allowed the mapping of areas of relatively high and low motility within a single field-of-view, and comparison of the total distribution of motility between samples. [摘要]  开发了一种方法,可以对密集样本中的相对细菌抽动动力进行定量和绘图,在这些样本中追踪单个细菌是不可行的。 在这种方法中,使用微分干涉对比显微镜(DIC)获得细菌膜的电影,然后通过细菌随时间调节视场中的光强度的程度间接量化细菌运动。 这允许在单个视场内绘制相对较高和较低运动性的区域,并比较样本之间运动的总分布。

【背景】Pilus介导的颤动运动表示与鞭毛无关的与表面相关的细菌运动形式。抽动动力被很多细菌病原体利用,包括淋病奈瑟氏球菌和铜绿假单胞菌与潮湿的表面相互作用并移位上皮屏障。在 P。颤动动力受大量基因调控,这些基因允许IV型菌毛的延伸和回缩,以有效地将细菌细胞拖过任何给定的表面以响应环境提示(Mattick,2002; Whitchurch et al。,2004; Burrows,2005)。在我们对 P的研究中。绿脓杆菌发病机制,抽动运动性有助于细菌在内化和多层角膜上皮细菌穿过后从上皮细胞排出(Alarcon等人,2009)。在角膜感染的小鼠模型中,抽动运动对于P是重要的。绿脓杆菌毒力(Zolfaghar et al。,2003)。最近,我们发现在粘膜液体如人眼泪和唾液中发现的糖蛋白DMBT1能够抑制P细胞。绿脓杆菌抽动动力(Li等人,2017)。在那项研究中,我们利用了一种新方法来快速和可靠地量化P.绿脓杆菌抽动动力。该协议在此处介绍。
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