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View additional product information for Geneticin™ Selective Antibiotic (G418 Sulfate) (50 mg/mL) - FAQs (10131027, 10131035)
14 product FAQs found
我们所有的抗生素（Geneticin，Zeocin，潮霉素B，杀稻瘟素和嘌呤霉素）均可共用于多重稳转细胞系的建立。不过，需要针对每一种抗生素组合来获取杀菌曲线，因为当与其他抗生素联用时，细胞对某一特定抗生素的灵敏性会出现增加的趋势。
当不可替代的培养物被污染时，研究人员可能会试图控制或消除污染。
1.用户需要确定污染的来源是细菌、真菌、支原体，还是酵母。请点击此处(https://www.thermofisher.com/us/en/home/references/gibco-cell-culture-basics/biological-contamination/bacterial-contamination.h%E2%84%A2l)阅读更多信息，以了解每一种污染的特性。
2.把受污染的培养物跟其他细胞系进行隔离。
3.使用一款实验室消毒剂清洁培养箱和层流柜，并检查HEPA过滤器。
4.高浓度的抗生素和抗真菌剂可能对一些细胞系有毒性。因此，需进行剂量效应测试来确定何种浓度水平的抗生素或抗真菌会造成毒性。这一操作对于使用Gibco Fungizone一类的抗真菌剂或泰乐菌素一类的抗生素尤其重要。
下列操作为我们确定毒性水平和对培养物去污染的推荐步骤：
1.对细胞进行分离，计数, 使用不含抗生素的培养基稀释将细胞稀释至常规传代的浓度。
2.将细胞悬液分入多孔培养板或几个小培养瓶中。向每一培养孔中添加不同浓度的特定抗生素。举例来说，我们推荐以如下浓度测试Gibco Fungizone试剂:0.25，0.50，1.0，2.0，4.0和8.0 µg/mL。
3.每日观察细胞脱落，出现空泡，融汇度降低，细胞变圆一类的毒性效应。
4.一旦确定了抗生素的毒性浓度水平，就可使用比毒性浓度低一至两倍的抗生素浓度来培养细胞两至三代。
5.在不含抗生素的培养基中培养一代。
6.重复步骤4。
7.在不含抗生素的培养基中培养细胞四至六代，以确定污染是否成功被消除。
请访问如下页面(https://www.thermofisher.com/us/en/home/life-science/cell-culture/mammalian-cell-culture/antibiotics.html)浏览我们提供的细胞培养相关的抗生素产品。
All of our antibiotics (Geneticin, Zeocin, Hygromycin B, Blasticidin, and Puromycin) can be used together for making multiple stable cell lines. However, kill curves will need to be performed for each combination of antibiotics since sensitivity to a given antibiotic tends to increase when combined with other antibiotics.
No, Neomycin is toxic to mammalian cells. It also causes irreversible damage to kidneys and other organs. Geneticin (aka G418 Sulfate) is a less toxic and very effective alternative for selection in mammalian cells. Neomycin can be used in bacterial selection, but Kanamycin is the preferred drug to use because of Neomycin's toxicity.
For best results, optimal concentrations for selection should be determined empirically in each unique experiment through dose response curves. However, to get a general idea of concentrations that have worked for individual cell types, please click on the following url: http://www.thermofisher.com/us/en/home/life-science/cell-culture/transfection/selection.html or type in “Selection Antibiotics” into our main search on www.thermofisher.com.
It is true that a percentage of non-resistant mammalian cells do not round-up from the plate upon Zeocin selection as would be seen with G418 or Hygromycin selection. However, one should see some very characteristic morphological changes occurring in those cells that are not resistant. These cells that stick to the culture dish typically display a vast increase in size. This could be best described as being similar to the effects of cytomegalovirus infecting permissive cells. The shape of these cells may also change; taking on an "alien" shape. On close examination of the non-resistant cells, the researcher should observe a distinct breakdown of both the nuclear and plasma membranes. Even though the "cells" are still attached to the plate, they should have the appearance of many holes in these membranes. Also, before the breakdown of the membranes, one can observe open areas in the cytoplasm of the cells that appear to be large, empty vesicles. Although not confirmed, this may be explained by a breakdown of the endoplasmic reticulum and Golgi apparatus, or other scaffolding proteins. Eventually, these "cells" will completely breakdown so that only "strings" of protein are left.
In contrast, Zeocin resistant cells should continue to divide at a regular interval to form distinct clumps of cells, or colonies. There should not be a distinct change in morphology, which can be compared to cells not under selection with Zeocin. It is these colonies of actively dividing cells that contain the resistance gene and are expressing it actively.
If there is concern about the dead cells sticking to the plate, one may do the following to eliminate them: Treat the plate for a couple of minutes with trypsin/versene. Both the healthy resistant cells and the dead cells will dislodge from the plate. The cells can then be replated (without Zeocin selection) and the healthy cells will attach again while the dead ones will not. After a couple of hours when the healthy cells have attached to the substrate again, Zeocin can be added back to the medium.
Blasticidin: Nucleoside Inhibits protein synthesis in prokaryotic and eukaryotic cells by interfering with peptidyl transfer reaction of protein synthesis, causing early termination of translation.
Geneticin (G418): Aminoglycoside Blocks protein synthesis in mammalian cells by interfering with ribosomal function.
Hygromycin: Aminocyclitol Inhibits protein synthesis by disrupting translocation and promoting mistranslation.
Zeocin: Intercalates with DNA and cleaves it.
The specific activity of Geneticin varies from lot to lot. To create a stock solution of Geneticin, obtain the potency from the label or Certificate of Analysis. Make a concentrated stock at 50 mg/ml active weight in sterile dI water, buffered salt solution, culture medium, or 100mM HEPES buffer. Note: Geneticin in water is acidic and adding it directly to the medium will often cause an immediate pH change, which will be plainly visible as a color change in medium containing phenol red. If the medium is well-buffered, the pH will return to normal in a matter of minutes to a few hours. If the pH change is of concern, you may wish to make the stock solution in buffered solution such as 100mM HEPES.
Sensitivity to G418 differs markedly depending on cell type, cell growth medium, and the serum supplement used. Experimentally determine the proper concentration for selection by setting up a dose response curve. Use concentrations between 100 ug/ml and 2 mg/ml G418 in medium, at 200 ug/ml increments. For more information, see the product insert.
We recommend Geneticin Selective Antibiotic (G418 Sulfate) (50 mg/mL) (Cat. Nos. 10131035, 10131027), which is in liquid form.
Find additional tips, troubleshooting help, and resources within our Cell Culture Support Center.
No. Geneticin Selective Antibiotic (G418 Sulfate) (50 mg/mL) (Cat. No. 10131027, 10131035) and Gentamycin are not interchangeable. Geneticin will kill agrobacterium unless it is transformed with a plasmid encoding the neomycin-resistance (neo) gene.
Find additional tips, troubleshooting help, and resources within our Cell Culture Support Center.
When an irreplaceable culture becomes contaminated, researchers may attempt to eliminate or control the contamination.
1. Determine if the contamination is bacteria, fungus, mycoplasma, or yeast. Read more here to view characteristics of each contaminant.
2. Isolate the contaminated culture from other cell lines.
3. Clean incubators and laminar flow hoods with a laboratory disinfectant, and check HEPA filters.
4. Antibiotics and antimycotics at high concentrations can be toxic to some cell lines. Therefore, perform a dose-response test to determine the level at which an antibiotic or antimycotic becomes toxic. This is particularly important when using an antimycotic such as Gibco Fungizone reagent or an antibiotic such as tylosin.
The following is a suggested procedure for determining toxicity levels and decontaminating cultures:
1. Dissociate, count, and dilute the cells in antibiotic-free media. Dilute the cells to the concentration used for regular cell passage.
2. Dispense the cell suspension into a multiwell culture plate or several small flasks. Add the antibiotic of choice to each well in a range of concentrations. For example, we suggest the following concentrations for Gibco Fungizone reagent: 0.25, 0.50, 1.0, 2.0, 4.0, and 8.0 µg/mL.
3. Observe the cells daily for signs of toxicity such as sloughing, appearance of vacuoles, decrease in confluency, and rounding.
4. When the toxic antibiotic level has been determined, culture the cells for two to three passages using the antibiotic at a concentration one- to two-fold lower than the toxic concentration.
5. Culture the cells for one passage in antibiotic-free media.
6. Repeat step 4.
7. Culture the cells in antibiotic-free medium for four to six passages to determine if the contamination has been eliminated.
Find additional tips, troubleshooting help, and resources within our Cell Culture Support Center.
Please view the following page to browse the cell culture antibiotics we offer (https://www.thermofisher.com/us/en/home/life-science/cell-culture/mammalian-cell-culture/antibiotics.html).
Find additional tips, troubleshooting help, and resources within our Cell Culture Support Center.