| Description | Inquire | Bacterial protein extraction reagents use mild non-ionic detergents and are suitable for extracting recombinant proteins expressed in Escherichia coli and insect cells. During the extraction process, there is no need for ultrasonic fragmentation, effectively avoiding contamination of exogenous Bacterial protein extraction reagents use mild non-ionic detergents and are suitable for extracting recombinant proteins expressed in Escherichia coli and insect cells. During the extraction process, there is no need for ultrasonic fragmentation, effectively avoiding contamination of exogenous proteins. This product can be applied to extract soluble proteins from bacterial lysates. The bacterial protein extraction kit adds a mixture of lysozyme, DNase I, and protease inhibitors to the extraction reagent, which can improve the efficiency of protein extraction and reduce the viscosity caused by DNA, effectively avoiding protein degradation. The extracted protein maintains biological activity and can be subjected to downstream operations such as IP, Western blot, and protein purification. Component B665764 100 preps Bacterial Protein Extraction Reagent 100 ml Protease Inhibitor Cocktail (100x) 1 ml Lysozyme （50 mg/ml） 200µl DNaseⅠ（1,000 U/ml） 100µl Notes:1. This product is suitable for extracting proteins from fresh or frozen bacterial and insect cells.2. This product uses Tris buffer system. Please use the same buffer system for protein purification after extraction.3. The protein lysis solution obtained from this product can be used for protein quantification using BCA or Bradford method.4. For special strains, if the extraction effect is not ideal, the sample can be frozen before protein extraction.5. Depending on the specific situation, protease inhibitors, salts, chelating agents, reducing agents, etc. can be added to this product.Operation steps: ● Insect cell protein extraction1. Collect cells by low-speed centrifugation. Add 10 to every 1 ml of Bacterial Protein Extraction Agent µ The Protein Inhibitor Cocktail is 1 x working fluid.2. Weigh the wet weight of the cells and add 1 x working solution at a rate of 10 ml/g.3. After resuspension, incubate on ice for 20 minutes (the ice storage time should be adjusted according to different cell types).Centrifuge at 4.15000 × g for 15 minutes to isolate soluble proteins. ● Extraction of soluble bacterial proteins 1. Centrifuge for 10 minutes at a rate of 5000 × g and collect the bacterial cells.2. Optional steps: Add 1 ml of Bacterial Protein Extraction Reagent every 1 ml µ DNase I (1000 U/ml), 2 µ Lysozyme (50 mg/ml) and 10 µ Protein Inhibitor Cocktail, vortex oscillation and mixing. 3. Add 20 ml of Bacterial Protein Extraction Reagent to each gram of bacterial precipitate, and add the extraction solution to the bacterial precipitate. Vortex thoroughly or use a pipette to blow up and down until the bacterial precipitate is completely resuspended.4. After resuspension, incubate at room temperature for 10-15 minutes (the storage time should be adjusted according to different cell types). 5. Centrifuge at 15000 × g for 5 minutes.6. Transfer the supernatant to a new centrifuge tube (the supernatant is soluble protein) for protein quantification and downstream experiments.Note: If the target protein exists in the form of inclusion bodies, inclusion body protein solution can be used for dissolution or expression conditions can be optimized to increase the expression of soluble proteins.Frequently asked questions: Problem Possible reasons Resolvent The target protein is insoluble The target protein is expressed as an inclusion body Optimize expression conditions or add Lysozyme and DNase I to protein extraction reagents using inclusion body protein solution After adding Lysozyme, the target protein has not been extracted yet Temperature too low Restore the reagent to room temperature After adding Lysozyme, the target protein has not been extracted yet Lysozyme Decreased or inactivated activity Add more Lysozymes or replace with new enzymes Extract has high viscosity DNase I Decreased or inactivated activity Add more DNase I or replace with a new DNase I to increase the final concentration of magnesium ions to 2 mM After protein extraction, most of the proteins still exist in the precipitate Excessive protein content Add Lysozyme and DNase I The protein extraction reagent has sediment precipitation Temperature too low Restore the protein extraction reagent to room temperature... Read More | Inquire | Inquire | The fluorescent dye PKH67 is suitable for conventional cell membrane labeling. It is a green fluorescent dye that can track cells in vitro and in vivo. It labels cells by binding to the lipid components of the membrane structure. PKH67 has low cytotoxicity, low fluorescence background, high fat The fluorescent dye PKH67 is suitable for conventional cell membrane labeling. It is a green fluorescent dye that can track cells in vitro and in vivo. It labels cells by binding to the lipid components of the membrane structure. PKH67 has low cytotoxicity, low fluorescence background, high fat solubility, can easily penetrate cell membranes, and has strong and stable green fluorescence. PKH67-labeled cells can be used for in vitro and in vivo proliferation studies, and have the function of not staining neighboring cells. In the process of cell division and proliferation, the fluorescence intensity of PKH67 will gradually decrease as the cells divide. The labeled fluorescence can be evenly distributed to the two sub-generation cells, so its fluorescence intensity is half that of the parent cell. According to this feature, It can be used to detect cell proliferation, cell cycle estimation and cell division, etc. The fluorescence of PKH67-labeled cells is very uniform, and the fluorescence distribution of sub-generation cells after division is also more uniform. In the process of cell division and proliferation, PKH67-labeled fluorescence can be evenly distributed between the two sub-generation cells, and the fluorescence intensity becomes half of that of the parent cell. According to the difference in fluorescence intensity, the undivided cells can be detected by flow cytometry. One time (1/2 the fluorescence intensity), the second time (1/4 the fluorescence intensity), three times (1/8 the fluorescence intensity), and more divisions of cells. PKH67 can detect splits up to six times or even more. In addition to the detection of cell proliferation, PKH67 can also be used for in vitro tracking of cells. After labeling, the fluorescence expression is stable in the cell, and the positive labeling rate is over 98%. The labeled cells have good morphology, which can effectively observe the cells in vitro. Induce differentiation; or inject labeled cells into the body, it can effectively show the migration and differentiation of transplanted cells in living tissues. PKH67-labeled cells can be used for in vivo observation for as long as several weeks. It is often used for in vivo cell detection experiments and experiments to observe long-term cell activity using fluorescence electron microscope. PKH67 is less toxic and does not affect cell proliferation. This method is simple to operate, does not use radioactive isotopes, and poses no safety hazards. You can get the desired experimental data faster, more accurately and more safely.Due to the longer length of the charcoal tail, internal studies have shown that PKH67 is less transferred between cells than PKH2. In in vivo studies using PKH1 and PKH2, the fluorescence intensity will slowly lose. Since this is a behavioral characteristic of green cell linker dye rather than red cell linker dye, PKH67 will have similar properties. The correlation between the in vitro cell membrane retention of non-dividing cells and the in vivo fluorescence half-life reveals that the in vivo fluorescence half-life of PKH67 is 10-12 days. Other green cell linker dyes with similar half-lives have been used to monitor the transport of lymphocytes and macrophages in the body within one to two months. The results indicate that PKH67 can also be used for medium-term in vivo tracking studies.The dye can stably bind to the lipid region of the cell membrane and emit fluorescence, and is mainly used for cell labeling in vitro, cell proliferation research in vitro, and cell tracing research in vivo and in vitro. The fluorescence half-life of PKH67 in vivo is 10-12 days. Compared with PKH-67, PKH-26 has a longer half-life, and the half-life of PKH26 labeled on rabbit red blood cells is more than 100 days. Especially suitable for in vitro proliferation research and long-term in vivo cell tracking research. After PKH67 labels the cells, flow cytometry is usually used for cell proliferation detection.Kit components0.1ml kits: P266290A-0.1ml P266290B-10ml1ml kits: P266290A-1ml P266290B-60mlDyes with A suffix and diluents with B suffix are used togetherPKH67 labeled cells show green fluorescence, the fluorescence wavelength: λex=490 nm, λem=502 nm.Storage conditions: -20℃ protected from light, valid for 1 yearPrecautions●Staining concentration varies according to the type of cell and the number of cells in each well.● The prepared PKH67 mother liquor is very easy to dissolve. It is recommended to store in aliquots and freeze-dry at ≦-20℃.● PKH67 working solution should be prepared for immediate use, and cannot be prepared in advance, because PKH67 will decompose due to the absorption of water and affect the dyeing effect.● PKH67 is easily decomposed and will deteriorate quickly in the water solution. Please avoid contact with water during use of mother liquor. The working fluid is in contact with the water during the process of labeling the cells within the permitted time range.● PKH67 fluorescent dye is a DMSO solution. It will solidify and stick to the bottom, wall or cap of the tube at a lower temperature such as 4℃ and ice bath. After being taken out of the refrigerator, it will return to room temperature and become After the liquid is in the state, remove the cap from the bottom of the tube. It can be used after it has completely melted in a 37°C water bath.● The number of generations or time that can be traced after different cell types are marked is quite different. Please make a test based on the actual situation or reference documents.Instructions1. Staining solution preparation:(1) Take out the PKH67 reagent from the refrigerator, let it stand for a few minutes to room temperature, or after a 37°C water bath, leave the tube containing PKH67, and be sure to leave the tube for a few minutes before opening the lid to allow the reagent to fully fall into the tube The lid can only be opened after the bottom.(2) According to the number of cell samples to be tested, dilute the probe 10 times with the diluent, and then use a suitable solution (such as non-clear medium, HBSS or PBS) to dilute the PKH67 mother liquor 25 times to prepare a stain Work fluid. The best working solution concentration should be adjusted according to different cells and your own experimental system. Generally, the cells can be diluted 250 times according to the final concentration of the mother liquor in the kit. Some cells may need to increase the concentration appropriately.2. Cell staining(1) Resuspend the prepared cells to be tested in 100µl of staining solution to a cell concentration of about 107/ml. You can also perform in-situ staining, as long as the staining solution is enough to cover the cells.(2) Culture the cells at 2～8℃ for 15～30 minutes. The best culture time is different for different cells.It is recommended to incubate the labeled cells in the staining solution at 37°C for 5 minutes, and then at 4°C for 15 minutes.Low-temperature incubation can reduce the endocytosis of the dye by the cells, help the dye to label the plasma membrane, and reduce the possibility of the dye localizing to cytoplasmic vesicles.(3) After separation, remove the supernatant, collect the cells, wash the cells 1-2 times with PBS or non-clear medium, and finally add PBS or non-clear medium to resuspend the cells.(4) Take 500µl of cell suspension and test with flow cytometer. Ex/Em=490/502nm.(5) Subsequently, the cells can be cultured according to the normal culture method.(6) The labeling effect can be directly observed under a fluorescence microscope, or the cell proliferation can be detected by a flow cytometer after an appropriate period of culture, or used for cell fluorescence traces for other specific experimental purposes... Read More |