背景介绍：
阿拉丁微球菌核酸酶（MNase），又名微球菌内切核酸酶、S7 核酸酶，源自金黄色葡萄球菌，CAS 号 9013-53-0，分子量约 18.6kDa，是 Ca²+ 依赖型核酸内切酶，在 pH7.0-10.0 下具备高效酶切活性。该酶可降解单 / 双链、线 / 环状等各类 DNA/RNA，生成 3' 磷酸末端的单 / 寡核苷酸，对单链核酸、AT/AU 富集区域切割效率更高，为相对非特异性核酸酶，可高效去除细胞裂解液核酸杂质，降低样品粘度。
其核心特性为仅酶切核小体连接区裸露 DNA，是染色质免疫沉淀（ChIP）的优选工具酶，适配 X-ChIP 和 N-ChIP 两种实验：X-ChIP 中酶切获 200-1000bp 片段，适用于低亲和力 DNA 结合蛋白研究；N-ChIP 中酶切生成 1-5 个核小体的片段，适配组蛋白修饰结合位点研究。
本产品酶活稳定、批次一致性好，是分子生物学实验及基因转录调控、表观遗传研究的可靠工具。
使用说明：
1. MNase的稀释:
如需对MNase进行稀释，为保证MNase的稳定性及降低被容器的吸附，建议使用添加了1X BSA的1XReaction Buffer作为稀释液进行梯度稀释。例如：取5μl MNase (2000 gel units/μl)加入到45μl稀释液中，充分吹打混匀，即得50μl 200 gel units/μl的MNase；再取5μl MNase (200 gel units/μl)加入到45μl稀释液中，充分吹打混匀，即得50μl 20 gel units/μl的MNase；依次往下进行梯度稀释。
2. MNase用于核酸或细胞样品的消化：
a. 按照下表加入相应试剂和样品:
Reagent | Volume(20µl system) | Volume (50µl system) | Final Concentration |
MNase | 1 µL | 2.5 µL | 1~2000 gel units |
Reaction Buffer (10X) | 2 µL | 5 µL | 1X |
BSA (100X) | 0.2 µL | 0.5 µL | 1X |
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要进行摸索。
注2：如果样品中不含蛋白质，则将BSA以1X的终浓度加入反应缓冲液中。如果是细胞样品，则无需添加BSA。
b. 适当混匀反应体系，37ºC孵育15-30分钟，或更长时间，直至核酸被消化完全或取得预期的消化效果。
c. 选做：加入适量0.5M EDTA pH8.0以终止反应，如20µl反应体系加入1µl 0.5M EDTA pH8.0，50µl反应体系加入2.5µl 0.5M EDTA pH8.0。
3. MNase用于ChIP实验中的染色质片段化。
注意事项：
1. 本品含50%甘油，-20ºC保存不会冻结。须避免-80ºC保存，冻融可能会降低本产品的酶活性。
2. 本品较为粘稠，吸取时注意取样量准确，加样后请注意充分吹打混匀，避免产生气泡。
3. Ca2+是MNase的关键催化辅助因子，反应缓冲液含有1-5mM Ca2+对MNase的酶活性是必须的，反应溶液中如有EDTA、EGTA等金属离子螯合剂会影响酶活性。
4. 反应溶液中盐离子浓度须低于100mM，过高的盐浓度会影响MNase的酶活性。
5. 如果样品中不含蛋白质，则将BSA以1X的终浓度加入反应缓冲液中。
Background Introduction:
Aladdin Micrococcal Nuclease (MNase), also known as Micrococcal Endonuclease or S7 Nuclease, is derived from Staphylococcus aureus (CAS No. 9013-53-0) with a molecular weight of approximately 18.6 kDa. It is a Ca²⁺-dependent endonuclease that exhibits high enzymatic activity within a pH range of 7.0–10.0. This enzyme degrades various forms of DNA/RNA, including single/double-stranded and linear/circular nucleic acids, producing mono- or oligonucleotides with 3'-phosphorylated ends. It shows higher cleavage efficiency toward single-stranded nucleic acids and AT/AU-rich regions, making it a relatively non-specific nuclease capable of efficiently removing nucleic acid contaminants from cell lysates and reducing sample viscosity.
A key characteristic of MNase is its ability to specifically cleave linker DNA between nucleosomes without digesting nucleosome-protected regions, making it an ideal enzyme for Chromatin Immunoprecipitation (ChIP). It is suitable for both X-ChIP and N-ChIP applications: in X-ChIP, digestion yields 200–1000 bp fragments suitable for studying low-affinity DNA-binding proteins; in N-ChIP, it generates fragments containing 1–5 nucleosomes, making it well-suited for investigating histone modification binding sites.
This product offers stable enzyme activity and excellent batch-to-batch consistency, serving as a reliable tool for molecular biology experiments, gene transcription regulation studies, and epigenetic research.
Instruction for use
1. Dilution of MNase:
If dilution of MNase is required, it is recommended to use 1X Reaction Buffer supplemented with 1X BSA as the diluent for serial dilution. This helps maintain the stability of MNase and reduces its adsorption to container surfaces.For example:Add 5 µL of MNase stock solution (2000 gel units/µL) to 45 µL of the diluent. Mix thoroughly by pipetting up and down. This yields 50 µL of MNase at a concentration of 200 gel units/µL.Then, take 5 µL of this diluted MNase solution (200 gel units/µL) and add it to 45 µL of fresh diluent. Mix thoroughly again. This yields 50 µL of MNase at a concentration of 20 gel units/µL.Subsequent dilutions can be performed by repeating this serial dilution process.
2. MNase is used for the digestion of nucleic acids or cell samples：
a. Add the corresponding reagents and samples according to the table below:
Reagent | Volume(20µl system) | Volume (50µl system) | Final Concentration |
MNase | 1 µL | 2.5 µL | 1~2000 gel units |
Reaction Buffer (10X) | 2 µL | 5 µL | 1X |
BSA (100X) | 0.2 µL | 0.5 µL | 1X |
Sample | x µL | x µL | - |
Water | (17-x) µL | (42-x) µL | - |
Total Volume | 20 µL | 50 µL | - |
Note 1: MNase may be appropriately diluted by referring to Step 1. The specific dilution factor and usage amount require optimization.
Note 2: If the sample does not contain protein, BSA should be added to the reaction buffer at a final concentration of 1X. For cell samples, no BSA addition is required.
b. Mix the reaction system properly and incubate at 37°C for 15–30 minutes, or longer as needed, until the nucleic acids are fully digested or the desired digestion results are achieved.
c. Optional: Add an appropriate amount of 0.5 M EDTA (pH 8.0) to stop the reaction. For example, add 1 µL of 0.5 M EDTA (pH 8.0) to a 20 µL reaction system, or add 2.5 µL to a 50 µL reaction system.
3. MNase for Chromatin Fragmentation in ChIP Experiments.
Matters needing attention
1. This product contains 50% glycerol and will not freeze when stored at -20°C. Storage at -80°C should be avoided, as freeze-thaw cycles may reduce the enzyme activity.
2. The product is relatively viscous. Please ensure accurate pipetting and mix thoroughly by pipetting up and down after addition to avoid bubble formation.
3. Ca²⁺ is a key catalytic cofactor for MNase. The reaction buffer must contain 1–5 mM Ca²⁺ to maintain enzyme activity. Metal ion chelators such as EDTA or EGTA in the reaction solution may inhibit enzyme activity.
4. The salt ion concentration in the reaction solution should be kept below 100 mM, as higher salt concentrations may impair MNase activity.
5. If the sample does not contain protein, BSA should be added to the reaction buffer at a final concentration of 1X.
ZJ26F0433904
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