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Fetal bovine serum (FBS)

胎牛血清

Company: Sigma-Aldrich
Catalog#: F7524
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Estimation of the Minimum Number of Replication Origins Per Chromosome in any Organism
Author:
Date:
2020-10-20
[Abstract]  Eukaryote nuclear genomes predominantly replicate through multiple replication origins. The number of replication origins activated per chromosome during the S-phase duration may vary according to many factors, but the predominant one is replication stress. Several studies have applied different approaches to estimate the number and map the positions of the replication origins in various organisms. However, without a parameter to restrict the minimum of necessary origins, less sensitive techniques may suggest conflicting results. The estimation of the minimum number of replication origins (MO) per chromosome is an innovative method that allows the establishment of a threshold, which serves as a parameter for genomic approaches that map origins. For this, the MO can be easily ... [摘要]  [摘要] 比率可能因多种因素而变化,但最主要的因素是复制应力。一些研究应用了不同的方法来估计复制源在不同生物体中的数量和位置。然而,如果没有一个参数来限制必要起源的最小值,那么不太敏感的技术可能会产生相互矛盾的结果。估计每个染色体的最小复制源数量(MO)是一种创新的方法,它允许建立一个阈值,作为绘制起源的基因组方法的参数。为此,MO可以很容易地通过一个公式得到,这个公式需要作为参数:染色体大小、S期持续时间和复制率。在基因组数据库(如NCBI)中可以获得任何生物体的染色体大小,通过监测DNA复制来估计S期的持续时间,并通过DNA组合方法获得复制率。 提供了一种简单、快速的估算MO的方法一个新的方法学框架来协助研究任何有机体。
关键词: DNA复制,复制来源,复制率,S期持续时间,染色体大小

[背景] ...

A Method to Efficiently Cryopreserve Mammalian Cells on Paper Platforms
Author:
Date:
2020-09-20
[Abstract]  This protocol describes a simple method to cryopreserve mammalian cells within filter papers as an alternative to conventional slow-freezing approach. The method involves treating paper fibers with fibronectin, using low concentrations of the cryoprotectant dimethyl sulfoxide (DMSO), and slow freezing cells to -80 °C at a 1 °C min-1 rate. In our method, the biocompatibility, large surface area, 3D porosity and fiber flexibility of the paper, in combination with the fibronectin treatment, yield recovery of cells comparable to conventional approaches, with no additional fine-tuning to freezing and thawing procedures. We expect that the paper-based cryopreservation method will bring several advantages to the field of preserving mammalian cells, including accommodation of a higher ... [摘要]  [摘要] 该协议描述了一种简单的方法,可在滤纸中冷冻保存哺乳动物细胞,以替代常规的慢速冷冻方法。该方法包括使用纤连蛋白处理纸纤维,使用低浓度的冷冻保护剂二甲基亚砜(DMSO),然后以1°C min -1的速率将细胞缓慢冷冻至-80°C 。在我们的方法中,纸的生物相容性,大表面积,3D孔隙率和纤维柔韧性与纤连蛋白处理相结合,可产生与传统方法相当的细胞回收率,而无需对冷冻和解冻程序进行额外的微调。我们期望纸质冷冻保存方法这将为保存哺乳动物细胞领域带来几项优势,包括在单位体积内容纳更多数量的细胞,并且释放后无细胞损失。该方法需要最小的存储空间,在该存储空间中,可以将具有大面积的纸平台卷起和/或折叠并存储在库存中,并允许按需方式有效地运输/分配细胞。此外,该方法的另一个特征包括细胞球体和3D细胞培养物的形成和冷冻保存。


[背景] 哺乳动物细胞的成功保存,长期保存,维护和分配是​​重要的研究领域,目前仍在深入的科学研究中。特别是,冷冻细胞的及时稳定供应与组织工程研究有关,例如细胞培养,药物开发和测试以及再生和生物治疗医学。

当前的常规细胞冷冻保存方案包括缓慢和快速的冷冻和玻璃化(Pegg,2002; Baust 等,2009)。在这些方法中,将各种浓度的冷冻保护剂添加到细胞悬浮液中,然后以低至1°C min -1 ...

Analyzing the Quenchable Iron Pool in Murine Macrophages by Flow Cytometry
Author:
Date:
2020-03-20
[Abstract]  Tissue-resident macrophages are pivotal for a tightly-regulated iron metabolism at a cellular and systemic level, since subtle iron alterations increase the susceptibility for microbial infections or drive multiple diseases. However, research on cellular iron homeostasis in macrophages remains challenging due to the limited amount of available methods using radioactive 59Fe isotopes or strong iron chelators, which might be inapplicable in certain experimental settings. This protocol describes the analysis of the quenchable iron pool (QIP) in macrophages by loading these cells with exogenous iron-complexes. Thereby, the cytoplasmic iron pool can be determined, since the iron uptake ability of macrophages inversely correlates with intracellular iron levels. Thus, this assay ... [摘要]  [摘要 ] 驻留在组织中的巨噬细胞对于在细胞和全身水平上严格调节铁代谢至关重要,因为细微的铁改变会增加对微生物感染的敏感性或引发多种疾病。然而,由于使用放射性59 Fe同位素或强铁螯合剂的可用方法数量有限,因此巨噬细胞中细胞铁稳态的研究仍然具有挑战性,这在某些实验环境中可能不适用。该协议 描述了通过向这些细胞加载外源铁配合物来分析巨噬细胞中的可淬灭铁池(QIP)。因此,由于巨噬细胞的铁摄取能力与细胞内铁水平成反比,因此可以确定细胞质的铁库。因此,该测定法能够准确分析细胞质铁通量的微小变化,并且几乎适用于所有实验室环境。另外,该方案还可以用于体外和体内的其他免疫细胞类型。

[背景 ] 由于用于全身铁代谢它们的中心调节功能,在多种组织中的巨噬细胞中迅速地改变在不同的刺激的遭遇它们的细胞内的铁水平的微生物感染和疾病(Nairz 等人,2017) 。值得注意的是,大多数细胞中的铁离子被细胞质中的主要铁存储蛋白铁蛋白结合或定位于线粒体或溶酶体等区室(Ma 等,2015 ; Soares和Hamza,2016 ...

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