Pen/Strep-PreMix CELLPURE ® Mechanism Penicillin inhibits cell wall biosynthesis in Gram-positive bacteria.Streptomycin produces the antibiotic effect in Gram-negative bacteria through inhibition of the translation. Directions for use The premixed powder is extremely stable during storage at room temperature and, due to the excellent solubility of the reagents in cell culture water (e.g. Art. No. 9186.1), it can be mixed quickly to a 100x stock solution. The dissolved antibiotics are stable for approx. 3 days at 37 °C. 50 ml of the 100x stock solution can be obtained directly by adding 49.2 ml cell culture water (Art. No. 9186.1). We recommend application in a 1:100 dilution. The stock solution mix (100 ml) is sufficient for 10 l medium. The final concentration of the 100x stock solution is: Penicillin: 10.000 I.U. / ml Streptomycin: 10 mg / ml Sodium chloride: 0.9 % Endotoxins Endotoxin content per vial: ≤210 l.U. complies ≤4.2 l.U. / ml