·产品描述

       组蛋白修饰是一种表观遗传修饰.翻译后的组蛋白修饰包括组蛋白乙酰转移酶介导的组蛋白赖氨酸残基乙酰化，组蛋白去乙酰化酶介导的去乙酰化，组蛋白甲基转移酶介导的赖氨酸和精氨酸的甲基化，组蛋白去甲基化酶介导的去甲基化，组蛋白磷酸化酶可以特定丝氨酸磷酸化，其他的修饰包括泛素化，SUMO化和聚ADP-核酸单位.除了DNA甲基化之外，组蛋白乙酰化和甲基化是最重要的表观遗传标记.总的说来，H3-K4， H3-K36或是H3-K79的三甲基化会导致一个开放的染色质构型，因而是常染色质的代表.常染色质以很高的组蛋白乙酰化为标志，而此特点是组蛋白乙酰化酶介导的.赖氨酸残疾可以被单、双或是三甲基化，每一种都可以不同程度上调节染色质结构和转录.还有其他的组蛋白修饰，比如磷酸化，这些修饰可以有不同的组合.以上这些组合形成了一个“组蛋白密码”，可以通过不同的细胞因素进行解读.

       EpiQuik组蛋白H3修饰定量试剂盒（比色法）是一组完全的、优化的试剂组合，可以同时定量H3上面21个修饰方式，是一个简单的Elisa检测方法.

·产品特点

1.同时检测21种不同的组蛋白H3修饰方式 

2.反应快速，在2.5h内完成 

3.创新的比色法让实验者摆脱了同位素，电泳，色谱或是其他昂贵的仪器 

4.高灵敏度是够检测限达到0.5ng/孔，可检测20ng-500ng/孔的组蛋白提取物 

5可以检测每一种H3修饰 

6.含有H3组蛋白标准品，可以对各种样品进行标准化 

7.实验灵活，可以进行单个修饰的处理，也可以进行21个修饰的处理 

8.额外的2条8孔板可以帮助进行上样量的优化，从而使检测结果落在检测限以内（20 ng to 500 ng/孔） 

9方案简单，可靠，稳定

·产品说明书

The EpiQuik™ Histone H3 Modification Multiplex Assay Kit (Colorimetric) is a complete set of optimized reagents to detect and quantify up to twenty-one (21) modified histone H3 patterns simultaneously in a simple, ELISA-like format with use of a standard microplate reader. The kit has the following advantages and features:

• Simultaneously screen and measure 21 different histone H3 modifications, which includes all of the most important and the most well-characterized patterns.
• Quick and efficient procedure, which can be finished within 2 hours and 30 minutes.
• Innovative colorimetric assay without the need for radioactivity, electrophoresis, chromatography, or expensive equipment.
• High sensitivity with a detection threshold as low as 0.5 ng/well for each modification pattern and a detection range from 20 ng to 500 ng/well of histone extracts.
• An assay control is conveniently included for quantification of each histone H3 modification.
• Total histone H3 sets are included, which can be used for normalizing total histone H3 levels for relative comparison of histone H3 content between different samples or different treatment conditions.
• Strip microplate format makes the assay flexible: manual or high throughput, which enables analysis of a single modification or total 21 modification patterns within the same samples.
• Two extra 8-well strips are included in the kit which can be used, if necessary, for sample amount pre-optimization to determine the input amount (ex: 50, 100, 200 ng/well) needed to fall within the detection limits of the assay. Extra strips may also be used as assay controls and total histone level controls if ive detection of some histone H3 modifications from the total 21 modification pattern is desired.
• Simple, reliable, and consistent assay conditions.

Background Information
Histone modifications have been defined as epigenetic modifiers. Post-translational modifications (PTMs) of histones include the acetylation of specific lysine residues by histone acetyltransferases (HATs), deacetylation by histone deacetylase (HDACs), the methylation of lysine and arginine residues by histone methytransferases (HMTs), the demethylation of lysine residues by histone demethylases (HDMTs), and the phosphorylation of specific serine groups by histone kinases (HKs). Additional histone modifications include the attachment of ubiquitin (Ub), small ubiquitin-like modifiers (SUMOs), and poly ADP-ribose (PAR) units. Next to DNA methylation, histone acetylation and histone methylation are the most well characterized epigenetic marks. Generally, tri-methylation at H3-K4, H3-K36, or H3-K79 results in an open chromatin configuration and is therefore characteristic of euchromatin. Euchromatin is also characterized by a high level of histone acetylation, which is mediated by histone acetyltransferases. Lysine residues can be mono-, di-, or tri-methylated, each of which can differentially regulate chromatin structure and transcription. Along with other histone modifications such as phosphorylation, this enormous variation leads to a multiplicity of possible combinations of different modifications. This may constitute a “histone code”, which can be read and interpreted by different cellular factors.

Principle & Procedure
In an assay with this kit, each histone H3 modified at specific sites will be captured by an antibody that is coated on the strip wells and specifically targets the appropriate histone modification pattern. The captured histone modified at specific sites will be detected with a detection antibody, followed by a color development reagent. The ratio of modified histone is proportional to the intensity of absorbance measured by a microplate reader at a wavelength of 450 nm.

Starting Materials
Input materials can be histone extracts or purified histone H3 proteins. The amount of histone extracts for each assay can be 20 ng to 500 ng with an optimal range of 50 ng to 100 ng depending on the purity of histone extracts. The amount of purified histone H3 proteins for each assay can be 1 ng to 25 ng with an optimal range of 4 ng to 5 ng.

Fig. 3. Histone extracts were prepared from MCF-7 and MDA-231 cells using the EpiQuik™ Total Histone Extraction Kit (Cat. No. OP-0006) and multiple histone H3 modifications were screened and measured using the EpiQuik™ Histone H3 Modification Multiplex Assay Kit (Colorimetric). 100 ng of total histone proteins were used.

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