Antibiotics

G418 also known as Geneticin(TM), is an aminoglycoside antibiotic that inhibits protein synthesis in mammalian cells by interfering with ribosomal function. G418 shows a structure similar to gentamycin > and kanamycin > and finds application in the selection of stably transformed cells expressing the neomycin resistance gene (aminoglycoside) of transposons Tn 5 or Tn 601.Because G418 is toxic for many cells, the optimum concentration for each cell type has to be determined. It is usually between 50ug/mL and 1000μg/mL. At a concentration of 500μg/mL, for example, 70% of HepG2 cells are killed after incubation for one week and 100% will stop their growth. Since potency of the antibiotic can vary from batch to batch, it is recommended to create large stocks of a batch tested to standardize the system.Cells divide still once or twice in the presence of the lethal dose of G418, so that a selection effect will be visible only after several days. Geneticin is a registered trademark of Gibco, a Division of Life Technologies. Genaxxon's G418 is an alternative to ThermoFisher / Invitrogen product no. 10131035 and 10131027, or a replacement for BioChrom product no.: A 2812. Genaxxon bioscience offers a broad range of Antibiotics and Antimycotics as powder or solutions.

G418 also known Geneticin(TM) is an aminoglycoside antibiotic that inhibits protein synthesis in mammalian cells by interfering with ribosomal function. Geneticin shows a structure similar to gentamycin > and kanamycin >, and finds application in the selection of stably transformed cells expressing the neomycin resistance gene (aminoglycoside) of transposons Tn 5 or Tn 601. Because G418 is toxic for many cells, the optimum concentration for each cell type has to be determined. It is usually between 50ug/mL and 1000μg/mL. At a concentration of 500μg/mL, for example, 70% of HepG2 cells are killed after incubation for one week and 100% will stop their growth.Since potency of the antibiotic can vary from batch to batch, it is recommended to create large stocks of a batch tested to standardize the system. Cells divide still once or twice in the presence of the lethal dose of G418, so that a selection effect will be visible only after several days. Geneticin is a registered trademarks of Gibco a Division of Life Technologies. Genaxxon's G418 is an alternative to ThermoFisher / Invitrogen product no. 10131035 and 10131027, or a replacement for BioChrom product no.: A 2812.

Pen-Strep: Penicillin G from Penicillium notatum and Streptomycin from Streptomyces griseus prevent together against gram-positive and gram-negative bacteria the bacterial contamination of cell cultures. Penicillin G acts by interfering directly with turnover of bacterial cell wall and indirectly by triggering release of enzymes that alter the cell wall. Streptomycin works by attaching to the 30S subunit of the bacterial ribosome, which leads to an inhibition of protein synthesis and the subsequent death of bacteria.Penicillin G potassium salt is soluble in water. At +4°C or room temperature, the dry substance is stable for approximately 5 years. The buffered solution (pH4,5-7) will loose 5% activity after 20 days at +4°C respective 20% after 60 days at +4°C. At room temperature, reduction in activity will be 5% after only 48 hours, 10% after 7 days, and 20% to 50% after 14 days. In an unbuffered solution stability is considerably lower (about 3-7 days at +4°C). Pen-Strep: Penicillin G and Streptomycin against bacterial contamination of cell cultures. Genaxxon bioscience offers besides Pen-Strep a broad range of Antibiotics and Antimycotics as powder or solutions, e.g., Geneticin G418 or Gentamycin sulfate.The minimum order quantity is 5 × M3140.0100 (100 mL).

Gentamycin is an almost ideal antibiotic for cell culture as it has a broad spectrum of antibacterial and antimycoplasmic activity. Gentamycin has biological and biochemical properties that make it superior to Penicillin and Streptomycin (PS). In cell culture, gentamycin is normally used at a concentration of 25 to 50μg/mL in the growth medium. Higher concentrations, e.g. 200μg/mL, are often used in viral studies when samples are known to be infected. As a broad-spectrum antibiotic, it can be used more widely and effectively than Penicillin/Streptomycin. Gentamicin is not only active against many Gram-positive and Gram-negative organisms, but also against Proteus and Staphylococcus strains, which can sometimes be resistant to a PS mixture. In addition, gentamicin is also active against Pseudomonas strains.Influence of the pH valueGentamicin shows good pH stability and has been shown to be stable in tissue culture media for 15 days, in a pH range of 2 to 10 and +37 °C. These are significant advantages over streptomycin, which is rapidly destroyed by alkaline conditions, and penicillin, which is unstable at both acidic and alkaline pH.Temperature stabilityGentamicin is stable at all temperatures and can even withstand autoclaving. When using autoclavable powder media, gentamicin can therefore be added before sterilization. In contrast, autoclaving leads to almost complete inactivation of penicillin and reduces the activity of streptomycin by 50%.Serum compatibilityCompared to pencillin, the activity of gentamycin is not affected by the presence of serum. Penicillin, on the other hand, immediately loses 30% of its activity when serum is added to the tissue culture medium.Cell tolerance and other aspects - Cells tolerate more than 20 times the normal concentration. - The use of gentamicin has no effect on viral yield or plaque formation. - Gentamicin has no effect on interferon yield or assays. Further use as an additive in mycological media to prevent bacterial growth. Gentamycin is ideal for use in cell and tissue cultures or the transport of cell cultures and clinical samples containing viruses.

Gentamycin is an almost ideal antibiotic for cell culture as it has a broad spectrum of antibacterial and antimycoplasmic activity. Gentamycin has biological and biochemical properties that make it superior to Penicillin and Streptomycin (PS). In cell culture, gentamycin is normally used at a concentration of 25 to 50μg/mL in the growth medium. Higher concentrations, e.g. 200μg/mL, are often used in viral studies when samples are known to be infected. As a broad-spectrum antibiotic, it can be used more widely and effectively than Penicillin/Streptomycin. Gentamicin is not only active against many Gram-positive and Gram-negative organisms, but also against Proteus and Staphylococcus strains, which can sometimes be resistant to a PS mixture. In addition, gentamicin is also active against Pseudomonas strains.Influence of the pH valueGentamicin shows good pH stability and has been shown to be stable in tissue culture media for 15 days, in a pH range of 2 to 10 and +37 °C. These are significant advantages over streptomycin, which is rapidly destroyed by alkaline conditions, and penicillin, which is unstable at both acidic and alkaline pH.Temperature stabilityGentamicin is stable at all temperatures and can even withstand autoclaving. When using autoclavable powder media, gentamicin can therefore be added before sterilization. In contrast, autoclaving leads to almost complete inactivation of penicillin and reduces the activity of streptomycin by 50%.Serum compatibilityCompared to pencillin, the activity of gentamycin is not affected by the presence of serum. Penicillin, on the other hand, immediately loses 30% of its activity when serum is added to the tissue culture medium.Cell tolerance and other aspects - Cells tolerate more than 20 times the normal concentration. - The use of gentamicin has no effect on viral yield or plaque formation. - Gentamicin has no effect on interferon yield or assays. Further use as an additive in mycological media to prevent bacterial growth. Gentamycin is ideal for use in cell and tissue cultures or the transport of cell cultures and clinical samples containing viruses.

Gentamycin sulfate is an aminoglycoside antibiotic and a metabolic product of Micromonospora purpurea. It is a mixture of 3 closely related components: C1 (approx. 20-40 %), C2 (approx. 40-60 %), and C1a (approx. 10-30 %) (Cox d. et al. (1977) Sammes, P.G (ed.) Topics in antibiotics chemistry Vol. I, Chichester, Horwood, pp. 1-190, Lancini G., Parenti F. (1982) Antibiotics: Springer, New York). The chemical formula and mol weights are: C19-21H39-43N5O7x2,5 H2SO4 with mol weights of 694.75 up to 723.75 g/mol. Gentamycin is active against Gram-positive and Gram-negative bacteria and Mycoplasma! Mechanism: Inhibits protein biosynthesis by binding to the 30 S ribosomal subunit and by destroying the cell membrane. The chemical formula and mol weights are: C19-21H39-43N5O7x2,5 H2SO4 with mol weights of 694.75 up to 723.75 g/mol. Gentamycin is active against Gram-positive and Gram-negative bacteria and Mycoplasma! Genaxxon bioscience offers a broad range of Antibiotics and Antimycotics > as powder or solutions, e.g., Geneticin G418 > or Kanamycin sulfate >.

Amphotericin B is a polyene antifungal that is used in cell culture to suppress fungal and yeast contamination, but does not act on bacteria. Addition of deoxycholate in phosphate buffer improves water solubility. For use: dilute 1: 100 (2.5μg/mL). Contains sodium deoxycholate. Amphotericin B is almost insoluble in water at pH6-7, at pH2 and pH11 soluble only with 100µg/mL. In DMSO 30-40mg/mL can be dissolved. Genaxxon bioscience offers a broad range of Antibiotics and Antimycotics > as powder or as solutions. Fungizone is a registered trademark of E.R. Squibb.

Antibiotic Antimycotic Solution (100X) for prevention of contamination by bacteria, yeasts and moulds. Penicillin G from Penicillium notatum and streptomycin from Streptomyces griseus prevent together against gram-positive and gram-negative bacteria bacterial contamination of cell cultures. Penicillin G acts by interfering directly with turnover of bacterial cell wall and indirectly by triggering release of enzymes that alter the cell wall. Streptomycin works by attaching to the 30S subunit of the bacterial ribosome, which leads to an inhibition of protein synthesis and the subsequent death of bacteria. Amphotericin B interferes with fungal membrane permeability by forming channels in the membranes and causing small molecules to leak out. Antimicrobial spectrum: Gram-negative bacteria, Gram-positive bacteria, fungi and yeasts. Recommended for use in cell culture applications at 10mL/L. Genaxxon bioscience offers a broad range of Antibiotics and Antimycotics as powder or solutions.The minimum order quantity is 5 × M3140.0100 (100 mL).

Apramycin is produced from Streptomyces tenebrarius. It is used to study antibiotic resistance as well as protein synthesis translocation-step inhibition in bacteria and prokaryotes. Apramycin is an aminoglycoside antibioticum and has a bactericidal action against many gram-negative bacteria. Apramycin inhibits protein synthesis by blocking translocation. It is also able to bind to the eukaryotic decoding site. At low concentrations it inhibits elongation and induces misreading of mRNA during protein synthesis. Apramycin is a structurally unique antibioticum that contains a bicyclic sugar moiety and a monosubstituted deoxystreptamine. Apramycin can only be acetylated by AAC-(3)IV and as a consequence of this enzymatic modification, the antibioticum is unable to enter the cell to bind to its ribosomal target. Apramycin (also Nebramycin II) is an aminoglycoside antibiotic used in veterinary medicine. It is used in pigs, sheep, cows, chicken and rabbits.

Bacitracin from Bacillus licheniformis consists of several peptides (A, B, C, D, E, F1-3), bacitracin A, a cyclic dodecapeptide, being the most important component with approximately 70%. For its bactericidal action, the presence of divalent cations (eg, zinc) is required, with which Bacitracin forms stable complexes. Like Vancomycin, it inhibits the biosynthesis of the cell wall (especially gram-positive bacteria and cocci) by binding to bactoprenylpyrophosphate. Bacitracin is very stable as a dry substance (moisture content <1%) with a shelf life of about 15 months at room temperature and is stable for about 15 months. At higher temperatures (>55°C) the antibiotic is unstable. Bacitracin is readily soluble in water or alcohols (1g/mL) and forms stable salts with zinc. In aqueous solutions, it is relatively stable in the acidic pH range (pH4-5) and relatively rapidly inactivated in the range above pH5 (pH5 - 9) at 25°C. Above pH8 it is not durable at all. In solution, 10% of the activity is lost at +2°C to +8°C within about 2 months.

Group of glycopeptide antibiotics from Streptomyces verticillus with antineoplastic properties by inhibition of DNA synthesis. Bleomycin sulfate is a mixture of bleomycin A2 and bleomycin B2 as the major components. Bleomycin sulfate occurs as a cream-colored, amorphous powder and is very soluble in water and sparingly soluble in alcohol. The potency of bleomycin is assayed microbiologically, the activity of 1 unit of bleomycin is equivalent to the activity of 1mg of bleomycin A2 reference standard. For chemistry and action of bleomycin, see: Umezaw, H. (1980) Med. Chem. 16, 147-66.

Doxycycline belongs to the generation of the newer tetracycline derivatives and is active against grampositive and gramnegative germs. Accordingly, it shows the same mechanism of action, i.e. an inhibition of the protein synthesis at the ribosomes. In the TET expression system, Doxycycline may replace Tetracycline >. The working concentration for the inactivation of tTA in double-stable cell lines is 1 - 20 ng/ml in the culture medium. Doxycycline is a broad spectrum inhibitor of metalloproteinases in vivo. Solubility and stability: The crystalline substance of Doxycycline is stable. The hyclate salt of Doxycycline is watersoluble. Stability of Doxycylcine in aqueous solutions depends on the pH value: an acidic pH value increases stability (more than 30 days at ambient temperature without loss of activity at pH 1 - 2,5). At pH 7 and ambient temperature, it is stable for more than 1 week. Doxycycline forms complexes with calcium ions, which leads to an inactivation of the antibiotic. Avoid high calcium concentrations in your assay. Genaxxon bioscience offers a broad range of Antibiotics and Antimycotics > as powder or solutions, e.g., Geneticin G418 >, Kanamycin > or Gentamycin sulfate >.

Aminoglycoside antibiotic that inhibits growth of procaryotic micro-organisms (bacteria), eukaryotic micro-organisms (yeast) and mammalian cells. Inhibits protein synthesis at translational step: causes misreading of mRNA. A gene from E.coli encoding resistance to hygromycin B can be isolated and cloned by recombinant DNA technology. It is useful for the identification or selection of recombinant clones in various cell types. The working concentration for mammalian cell selection is normally between 50µg/mL and 1mg/mL, plant cells: 20µg/mL-200µg/mL, bacteria: 20µg/mL-200µg/mL and Fungi: 200µg/mL - 1mg/mL. The appropriate concentration should be tested experimentally. Genaxxon bioscience offers a broad range of Antibiotics and Antimycotics > as powder or solutions, e.g., Geneticin G418 > or Kanamycin sulfate >.

Kanamycin is very stable as a solution in the pH range 6-8 and can be stored for 6-8 months at room temperature (with only 1-2% loss of activity). Autoclaving at 120°C (even for more than 1 hour) leads to only a slight loss of activity (5%). When exposed to air, Kanamycin may change colour but without losing much of its activity. The change in colour can be prevented by antioxidants. Aminoglycoside-antibiotic with broad antibacterial spectrum, (including mycobacteria, many gram-positive and most gram-negative organisms), Additive in culture media for the isolation of group D Streptococci on Kanamycin Esculin Azide Agar (Mossel et al.) or for selection of transformed plant cells containing the neomycin phosphotransferase (for kanamycin resistance), on a kanamycin-medium. Inhibits formation of peptide bonds, Cox d. et al. (1977) Sammes, P.G (ed.) Topics in antibiotics chemistry Vol. I, Chichester, Horwood, pp. 1-190, Lancini G., Parenti F. (1982) Antibiotics: Springer, New York, Pestka S. (1971) Annu. Rev. Microbiol. 25, 487-562.

Aminoglycoside-antibiotic with broad antibacterial spectrum, (including mycobacteria, many gram-positive and most gram-negative organisms), Additive in culture media for the isolation of group D Streptococci on Kanamycin Esculin Azide Agar (Mossel et al.) or for selection of transformed plant cells containing the neomycin phosphotransferase (for kanamycin resistance), on a kanamycin-medium. Inhibits formation of peptide bonds, Cox d. et al. (1977) Sammes, P.G (ed.) Topics in antibiotics chemistry Vol. I, Chichester, Horwood, pp. 1-190, Lancini G., Parenti F. (1982) Antibiotics: Springer, New York, Pestka S. (1971) Annu. Rev. Microbiol. 25, 487-562.