关键差异 - DNA与RNA提取
研究DNA和RNAare vital aspects in order to understand the basic concepts of分子生物学,生物技术, 和遗传学。为了在这些研究中进行实验程序,需要提取纯DNA和RNA样品。DNA和RNA提取之间的关键区别在于DNA提取过程净化DNA,而RNA提取净化RNA。DNA extraction process has three different steps: cell lysis andcatabolism膜脂质和蛋白质,通过浓缩盐溶液将分解代谢物汇总,DNA与与ethanol。The three step procedure may consist of two optional steps. RNA purification process consists of four different steps: addition of guanidium thiocyanate for cell lysis, protein denaturation including ribonucleases, separation of RNA by the addition of chloroform andphenol以及使用乙醇洗涤沉淀物。
内容
1.Overview and Key Difference
2.What is DNA Extraction
3.什么是RNA提取
4.Similarities Between DNA and RNA Extraction
5。Side by Side Comparison – DNA vs RNA Extraction in Tabular Form
6。概括
什么是DNA提取?
DNA提取是一种物理和化学过程,用于从样品中纯化DNA。在分子生物学和法医科学的背景下,DNA提取是一个重要方面。该过程是三个基本步骤。最初,应获得感兴趣的细胞。接下来,促进细胞裂解以破坏细胞膜,从而打开细胞并暴露细胞质along with DNA. Surfactants or other detergents can be utilized to lyse the lipids from the cell membrane while the proteins present are catabolized by proteases. This is an optional step. Once the cell is lysed, clumping of the catabolized molecules is facilitated by concentrated salt solutions. It is followed by centrifugation of the solution which separates the debris clumps from DNA. In this stage, the differentiated DNA is mixed with the reagents and salts used during the cell cycle.
为了进一步净化它,可以使用以下步骤。一种方法是乙醇沉淀,涉及将冰冷乙醇与分离的DNA样品混合。DNA不溶于酒精,因此由于DNA分子聚集在一起而产生沉淀。在此过程中添加乙酸钠,以通过增加离子强度来增强沉淀程度。除了乙醇沉淀过程外,还可以诱导苯酚 - 氯仿提取过程。在这种方法中,苯酚贬低了样品中存在的蛋白质。一旦离心,变性蛋白将保留在有机相中,而与氯仿混合的DNA分子将存在于水相中。氯仿将去除苯酚残基。提取完成后,将DNA溶解在TE缓冲液或超纯水中。
什么是RNA提取?
RNA purification is a process by which RNA is purified from a biological sample. Due to the presence of ribonuclease in the cells and tissues, this process is complicated. Ribonuclease enzyme has the ability to degrade RNA rapidly. The chemical nature of ribonucleases is extremely stable, and it is hard to inactivate them. Neutralizing the ribonucleases is an option. Since this enzyme is ubiquitous in the cells and tissues, special techniques are developed for RNA extraction. Out of the many methods, the common method is Guanidinium thiocynate-phenol-chloroform extraction.
The Guanidinium thiocynate-phenol-chloroform extraction method depends oncentrifugationand phase separation. The mixture to be centrifuged consists of the aqueous sample and a water saturated solution that consist of phenol and chloroform. Once centrifuged, the solution consists of an upper aqueous phase and a lower organic phase under neutral pH conditions (pH 7-8). RNA is present in the aqueous phase. The organic phase typically consists of proteins dissolved in phenol and lipids dissolved in chloroform. A chaotropic agent (a molecule that has the ability to break the hydrogen bonds between water molecules) is added; this is known as, guanidinium thiocyanate. This agent has the ability to denature proteins which include ribonucleases that can degrade RNA and is involved in cell lysis. It also separates rRNA from ribosomal proteins. The final step of RNA purification is washing the precipitation of the aqueous phase with ethanol. RNA could also be purified using liquid nitrogen.
DNA和RNA提取之间有什么相似之处?
- Both extraction processes utilize harmful chemicals such as phenol and chloroform.
- Centrifugation is an essential technique for both processes.
- Ethanol is used to wash the precipitate and to obtain purified DNA or RNA.
DNA和RNA提取之间有什么区别?
DNA与RNA提取 |
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DNA extraction is a process which extracts DNA from an organism or sample. | RNA提取是从样品中提取RNA的过程。 |
脚步 | |
The DNA extraction process is composed of three different steps with two optional steps. | RNA提取过程由四个不同的步骤组成。 |
Reagents | |
表面活性剂,蛋白酶(可选),酒精,氯仿,苯酚,乙酸钠用于DNA提取。 | 硫苷硫氰酸硫醇,氯仿,苯酚,乙醇用于RNA提取。 |
概括– DNA vs RNA Extraction
DNA和RNA提取是研究分子生物学,遗传学和生物技术的实验程序的重要方面。这两个过程均涉及类似的试剂,但是RNA提取使用了一种特殊的试剂,称为硫氰酸鸟酮,可减少核糖核酸的活性。这是DNA和RNA提取之间的主要区别。
下载DNA与RNA提取的PDF版本
You can download PDF version of this article and use it for offline purposes as per citation note. Please download PDF version hereDNA和RNA提取之间的差异
Reference:
1. Chomczynski, P, and N Sacchi. “Single-Step method of RNA isolation by acid guanidinium thiocyanate-Phenol-Chloroform extraction.” Analytical biochemistry., U.S. National Library of Medicine, Apr. 1987,Available here。2017年8月31日访问
2. Hindawi. “DNA, RNA, and Protein Extraction: The Past and The Present.” BioMed Research International, Hindawi, 30 Nov. 2009,Available here。2017年8月31日访问。
Image Courtesy:
1. “DNA extracted from avocado” By Mike Seyfang – originally posted to Flickr as success(CC由2.0)viaCommons Wikimedia
2. Squidonius(谈话)的“ Phoh-Chcl3提取” - 通过Commons Wikimedia
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