Penicillin/Streptomycin (Pen/Strep) is a ready-to-use antibiotic mix of penicillin and streptomycin. It is widely used in cell culture and can be added to cell culture media. Penicillin/Streptomycin is effective against contaminations with gram-positive and gram-negative bacteria. This product is provided as a 100x concentrate. Penicillins belong to the β-lactam family and act by inhibiting an essential enzyme for the synthesis of new membrane components (D-Alanin-Transpeptidase). Therefore penicillin is only effective on actively dividing cells. Streptomycin, on the other hand, acts by binding to the 30S subunit of the bacterial ribosome. This mechanism inhibits protein synthesis within the bacterium, regardless of whether the cell is actively dividing or not.Penicillin/Streptomycin (Pen/Strep) is a ready-to-use antibiotic mix of penicillin and streptomycin. It is widely used in cell culture and can be added to cell culture media. Penicillin/Streptomycin is effective against contaminations with gram-positive and gram-negative bacteria. This product is provided as a 100x concentrate. Penicillins belong to the β-lactam family and act by inhibiting an essential enzyme for the synthesis of new membrane components (D-Alanin-Transpeptidase). Therefore penicillin is only effective on actively dividing cells. Streptomycin, on the other hand, acts by binding to the 30S subunit of the bacterial ribosome. This mechanism inhibits protein synthesis within the bacterium, regardless of whether the cell is actively dividing or not.