ER2566热激感受态细胞

ER2566：                                                    100μl/支

pUC19 (control vector，10pg/μl):                    10μl

保存条件(保质期)：                             -80℃（6个月） 

ER2566热激感受态细胞基因型

F- λ- fhuA2 [lon] ompT lacZ::T7 gene1 gal sulA11 Δ(mcrC-mrr)114::IS10 R(mcr-73::miniTn10-TetS)2 R(zgb-210::Tn10)(TetS) endA1 [dcm]

产品说明

ER2566菌株是NEB公司开发的具有超高转化效率的蛋白表达原核菌株，来源于BL21。Lac启动子启动下游T7RNA聚合酶的表达，可用于T7启动子表达载体(如pET系列)的高水平蛋白表达。fhuA2赋予ER2566菌株对噬菌体T1的抗性。同时ER2566为lon 和 ompT蛋白酶缺陷菌株。Lon蛋白酶和膜外蛋白酶OMPT的缺失能够有效抑制表达的异源蛋白在大肠杆菌体内的降解，Δ(mcrC-mrr)114，mcr-73突变的存在使ER2566菌株无法对外源DNA进行标记、限制，提高了外源甲基化DNA的转化效率。ER2566感受态细胞由特殊工艺制作，pUC19质粒检测转化效率达10⁹ cfu/μg DNA。

ER2566热激感受态细胞操作方法

1.ER2566感受态细胞从-80℃拿出，迅速插入冰中，5分钟后待菌块融化，加入目的DNA（质粒或连接产物）并用手拨打EP管底轻轻混匀(避免用枪吸打)，冰中静置25分钟。

2. 42℃水浴热激45秒，迅速放回冰上并静置2分钟，晃动会降低转化效率。

3. 向离心管中加入700μl不含抗生素的无菌培养基(2YT或LB)，混匀后37℃，200rpm复苏60分钟。

4. 5000rpm离心一分钟收菌，留取100μl左右上清轻轻吹打重悬菌块并涂布到含相应抗生素的2YT或LB培养基上。

5. 将平板倒置放于37℃培养箱过夜培养。

Sample Induction Protocol (for reference only)

1.Inoculate a single colony from a freshly streaked plate into 5 ml of LB medium containing the appropriate antibiotic for the plasmid and host strain.

2.Incubate with shaking at 200 rpm at 37℃ overnight.  

3.Inoculate 50 ml of LB medium containing the appropriate antibiotic with 0.5 ml of the overnight culture prepared in step 2(use the 500 ml triangular flask as the container would be better).

4.Incubate with shaking at 150 rpm at 37℃ until the OD 600 reaches 0.5-0.8.

5.(Optional)Pipet 1ml of  the cultures into clean microcentrifuge tubes and  place the tubes on ice until  needed  for gel analysis or storage at  -20℃. These will serve as the non-induced control samples.  

6.Add IPTG to a final concentration of 1 mM.  Optimal time for induction of the target protein may vary from 2-16 hours, depending on the protein.

7.Incubate with shaking at 120 rpm at 37℃ for 3-4 hours. To determine the optimal time for induction of the target protein, it is recommended that a time course experiment be performed varying the induction from 2-16 hours.

8.Place the culture on ice for 10 minutes. Harvest cells by centrifugation at 5,000×g for 10 min at 4℃.

9.Remove the supernatant and store the cell pellet at -20℃ (storage at lower temperatures is also acceptable).  

IPTG 

Prepare a 1 M solution of IPTG (Isopropyl-β-D-thiogalactoside; Isopropyl-β-D-thiogalactopyranoside) by dissolving 2.38 g of IPTG in dd water and adjust the final volume to 10 ml. Filter sterilize before use.  

ER2566热激感受态细胞注意事项

1. 感受态细胞*在冰中缓慢融化，插入冰中8分钟内加入目标DNA，不可在冰中放置时间过长，长时间存放会降低转化效率。

2. 混入质粒时应轻柔操作。

3. 转化高浓度的质粒可相应减少最终用于涂板的菌量。

4. 诱导时，IPTG浓度可选（0.1-2mM均可）。

5. 为获得需要量的蛋白，*诱导时间，温度，IPTG浓度需实验者优化。