本公司生产的微球菌核酸酶（Micrococcal Nuclease, MNase, EC 3.1.31.1, CAS 9013-53-0）是一种源自金黄色葡萄球菌的 Ca²⁺依赖型核酸内切酶，分子量约 18.6 kDa，最适 pH 7-10。该酶可切割单链、双链、线状、环状 DNA 或 RNA，产生 3′- 磷酸末端的单核苷酸和寡核苷酸；对单链核酸的切割效率更高，且在 A/T/U 5′侧的切割效率约为 G/C 的 30 倍，表现出 “相对” 非特异性。MNase 仅攻击核小体连接区 DNA，而核小体 DNA 受组蛋白保护，因此成为染色质结构研究的重要工具。在染色质免疫沉淀（ChIP）实验中，MNase 可在交联（X-ChIP）或非交联（N-ChIP）条件下，将染色质精准酶切为 200 bp 或 1-5 个核小体大小的片段，既保留蛋白 - DNA 相互作用，又避免超声破碎带来的随机损伤，广泛应用于转录因子定位、组蛋白修饰及表观遗传调控研究。此外，MNase 也可用于去除细胞裂解液中的核酸，降低裂解液黏度，提升下游实验效率。
| 来源 (Source) | 大肠杆菌重组表达 |
|---|
| 分子量 (Molecular Weight) | 18.6 kDa |
| 外观 (Appearance) | 无菌液体 |
| 保存液 (Storage Buffer) | 5 mM Tris (pH 7.4), 50 mM NaCl, 1 mM EDTA, 50% Glycerol。本产品同时提供 100× BSA 用于 MNase 的稀释。 |
| 酶浓度 (Enzyme Concentration) | 2000 gel units/μl |
| 纯度 (Purity) | ≥95% |
| 活性定义 (Activity Definition) | One Agarose Gel Unit is defined as the amount of enzyme required to digest 1 μg of Lambda DNA at 37℃ for 15 minutes, resulting in the accumulation of low molecular weight DNA fragments of ＜400 bp as determined by agarose gel electrophoresis. Another activity unit is Kunitz Unit. One Kunitz Unit is defined as the amount of enzyme required to release acid-soluble oligonucleotides that produce an absorbance increase of 1.0 OD at 260 nm at 37℃ for 30 minutes. 1000 Agarose Gel Units is approximately equal to 100 Kunitz Units. |
组分和说明
M1518341
| Component | 320KU
| 5×320KU
| Storage |
| M1518341A | MNase (2000 gel units/μl)
| 160μl
| 5×160μl
| -20℃. Avoid freeze/ Thaw cycle. |
| M1518341B | Reaction Buffer (10×) | 1.6ml | 5×1.6ml
| -20℃. Avoid freeze/ Thaw cycle. |
| M1518341C | BSA (100×) | 250μl | 5×250μl
| -20℃. Avoid freeze/ Thaw cycle. |
产品应用
降解蛋白制剂中的核酸、体外翻译、在非机械法细胞裂解制备中降低细胞裂解物的黏度、染色质结构分析、快速 RNA 测序。
产品优势
MNase 用于染色质免疫沉淀实验时，具有样品完整性好、酶切条件温和等优势，也常应用于染色质免疫沉淀实验中的染色质片段化步骤。
使用说明
1. MNase 的稀释。如需对 MNase 进行稀释，为保证酶的稳定性并降低其被容器的吸附，建议使用添加了 1× BSA 的 1× Reaction Buffer 作为稀释液进行梯度稀释。示例：取 5 μl MNase（2000 gel units/μl）加入 45 μl 稀释液中，充分吹打混匀，即得 50 μl 200 gel units/μl 的 MNase；再取 5 μl 该浓度 MNase（200 gel units/μl）加入 45 μl 稀释液中，充分吹打混匀，即得 50 μl 20 gel units/μl 的 MNase；依此进行梯度稀释。
2. MNase 用于核酸或细胞样品的消化。
a. 按下表加入相应试剂和样品。
| Reagent | Volume (20 μl system) | Volume (50 μl system) | Final Concentration |
|---|
| Reaction Buffer (10×) | 2 μl | 5 μl | 1× |
| MNase* | 1 μl | 2.5 μl | 1~2000 gel units |
| BSA (100×)* | 0.2 μl | 0.5 μl | 1× |
| Sample | x μl | x μl | - |
| Water | (17-x) μl | (42-x) μl | - |
| Total Volume | 20 μl | 50 μl | - |
注 1：MNase 可参考步骤 1 进行适当稀释，具体稀释倍数及使用量需通过预实验摸索。
注 2：若样品中不含蛋白质，需将 BSA 以 1× 终浓度加入反应缓冲液；若为细胞样品，则无需添加 BSA。
b. 将反应体系轻轻混匀，37℃孵育 15-30 分钟（或更长时间），直至核酸被完全消化或达到预期的消化效果。
c. 选做步骤：加入适量 0.5 M EDTA (pH 8.0) 终止反应，如 20 μl 反应体系加入 1 μl 0.5 M EDTA (pH 8.0)，50 μl 反应体系加入 2.5 μl 0.5 M EDTA (pH 8.0)。
3. MNase 用于 ChIP 实验中的染色质片段化。具体实验方法请参考相关产品的文献资料。
注意事项
1. 本产品含 50% 甘油，-20℃保存时不会冻结；严禁于 - 80℃保存，冻融会降低酶活性。
2. 本产品黏度较高，吸取时需保证取样量准确；加样后充分吹打混匀，避免产生气泡。
3. Ca²⁺是 MNase 的关键催化辅助因子，反应缓冲液中需含有 1-5 mM Ca²⁺以保证酶的催化活性；反应体系中若存在 EDTA、EGTA 等金属离子螯合剂，会抑制酶活性。
4. 反应体系中的盐离子浓度需低于 100 mM，过高的盐浓度会影响 MNase 的酶活性。
5. 若样品中不含蛋白质，需将 BSA 以 1× 终浓度加入反应缓冲液。
6. 本产品仅限专业人员用于科学研究，不得用于临床诊断或治疗，不得用于食品、药品生产，不得在普通住宅内存放。
7. 为保障您的安全与健康，操作时请穿戴实验服并佩戴一次性手套。
The Micrococcal Nuclease (MNase, EC 3.1.31.1, CAS 9013-53-0) produced by our company is a Ca²⁺-dependent endonuclease derived from Staphylococcus aureus, with a molecular weight of approximately 18.6 kDa and an optimal pH range of 7-10. It can cleave single-stranded, double-stranded, linear and circular DNA or RNA, generating mononucleotides and oligonucleotides with 3′-phosphate ends. It has higher cleavage efficiency for single-stranded nucleic acids, and its cleavage efficiency at the 5′ side of A/T/U is about 30 times that at G/C, showing "relative" non-specificity. MNase only attacks the DNA in the nucleosome linker region, while nucleosomal DNA is protected by histones, making it an essential tool for chromatin structure research. In Chromatin Immunoprecipitation (ChIP) assays, MNase can precisely digest chromatin into fragments of 200 bp or 1-5 nucleosomes under cross-linked (X-ChIP) or non-cross-linked (N-ChIP) conditions. It not only preserves protein-DNA interactions but also avoids random damage caused by sonication, and is widely used in the localization of transcription factors, histone modification and epigenetic regulation research. In addition, MNase can also be used to remove nucleic acids from cell lysates, reduce lysate viscosity and improve the efficiency of downstream experiments.
| Source | Recombinant expression in Escherichia coli |
|---|
| Molecular Weight | 18.6 kDa |
| Appearance | Sterile liquid |
| Storage Buffer | 5 mM Tris (pH 7.4), 50 mM NaCl, 1 mM EDTA, 50% Glycerol. 100× BSA is provided with this product for MNase dilution. |
| Enzyme Concentration | 2000 gel units/μl |
| Purity | ≥95% |
| Activity Definition | One Agarose Gel Unit is defined as the amount of enzyme required to digest 1 μg of Lambda DNA at 37℃ for 15 minutes, resulting in the accumulation of low molecular weight DNA fragments of ＜400 bp as determined by agarose gel electrophoresis. Another activity unit is Kunitz Unit. One Kunitz Unit is defined as the amount of enzyme required to release acid-soluble oligonucleotides that produce an absorbance increase of 1.0 OD at 260 nm at 37℃ for 30 minutes. 1000 Agarose Gel Units is approximately equal to 100 Kunitz Units. |
Components and Description
M1518341
| Component | 320KU
| 5×320KU
| Storage |
| M1518341A | MNase (2000 gel units/μl)
| 160μl
| 5×160μl
| -20℃. Avoid freeze/ Thaw cycle. |
| M1518341B | Reaction Buffer (10×) | 1.6ml | 5×1.6ml
| -20℃. Avoid freeze/ Thaw cycle. |
| M1518341C | BSA (100×) | 250μl | 5×250μl
| -20℃. Avoid freeze/ Thaw cycle. |
Product Applications
Degradation of nucleic acids in protein preparations, in vitro translation, reduction of cell lysate viscosity in non-mechanical cell lysis preparation, chromatin structure analysis, rapid RNA sequencing.
Product Advantages
When used in ChIP assays, MNase has the advantages of good sample integrity and mild digestion conditions, and is also commonly used for chromatin fragmentation in ChIP assays.
Usage Instructions
1. Dilution of MNase. If MNase dilution is required, to ensure enzyme stability and reduce its adsorption to containers, it is recommended to use 1× Reaction Buffer supplemented with 1× BSA as the dilution buffer for serial dilution. Example: Add 5 μl of MNase (2000 gel units/μl) to 45 μl of dilution buffer, pipette up and down thoroughly to mix, and 50 μl of MNase with a concentration of 200 gel units/μl is obtained. Then add 5 μl of this MNase (200 gel units/μl) to 45 μl of dilution buffer, pipette up and down thoroughly to mix, and 50 μl of MNase with a concentration of 20 gel units/μl is obtained. Perform serial dilution in this manner.
2. Digestion of nucleic acid or cell samples with MNase.
a. Add the corresponding reagents and samples according to the table below.
| Reagent | Volume (20 μl system) | Volume (50 μl system) | Final Concentration |
|---|
| Reaction Buffer (10×) | 2 μl | 5 μl | 1× |
| MNase* | 1 μl | 2.5 μl | 1~2000 gel units |
| BSA (100×)* | 0.2 μl | 0.5 μl | 1× |
| Sample | x μl | x μl | - |
| Water | (17-x) μl | (42-x) μl | - |
| Total Volume | 20 μl | 50 μl | - |
Note 1: MNase can be appropriately diluted with reference to Step 1, and the specific dilution multiple and usage amount need to be optimized by pre-experiments.
Note 2: If the sample contains no protein, add BSA to the reaction buffer to a final concentration of 1×; no BSA is required for cell samples.
b. Mix the reaction system gently and incubate at 37℃ for 15-30 minutes (or longer) until the nucleic acids are completely digested or the expected digestion effect is achieved.
c. Add an appropriate amount of 0.5 M EDTA (pH 8.0) to terminate the reaction, e.g., add 1 μl of 0.5 M EDTA (pH 8.0) to a 20 μl reaction system, and 2.5 μl of 0.5 M EDTA (pH 8.0) to a 50 μl reaction system.
3. Chromatin fragmentation in ChIP assays with MNase. Please refer to the literature of relevant products for the specific experiment.
Notes
1. This product contains 50% glycerol and will not freeze when stored at -20℃. Do not store at -80℃, as freeze-thaw cycles will reduce enzyme activity.
2. This product has high viscosity, ensure accurate sampling volume when pipetting; pipette up and down thoroughly to mix after sample addition to avoid bubble formation.
3. Ca²⁺ is a key catalytic cofactor for MNase, the reaction buffer must contain 1-5 mM Ca²⁺ to ensure the catalytic activity of the enzyme; the presence of metal ion chelators such as EDTA and EGTA in the reaction system will inhibit enzyme activity.
4. The salt ion concentration in the reaction system must be lower than 100 mM, as excessively high salt concentration will affect the activity of MNase.
5. If the sample contains no protein, add BSA to the reaction buffer to a final concentration of 1×.
6. This product is only for scientific research by professional personnel, not for clinical diagnosis or treatment, not for the production of food and pharmaceuticals, and not for storage in ordinary residential buildings.
7. For your safety and health, wear a lab coat and disposable gloves during operation.
ZJ26F0535488
危险品化学品经营许可证（带存储）