Penicillin-Streptomycin-Neomycin Solution (PSN), 100×, (100 mL)

Penicillin-streptomycin solution mixture is the most commonly used antibiotic to prevent microbial contamination in vitro. Penicillin can interfere with the synthesis of bacterial cell wall, especially for Gram-positive bacteria. Streptomycin could bind to ribosomal ribosome for 30S and inhibit the synthesis of bacterial protein. It was effective for Gram-negative bacteria and Gram-positive bacteria, but especially for Gram-negative bacteria. Neomycin can bind to the 30S and 50S subunits of the bacterial ribosome to cause protein miscoding, and is effective against both Gram-negative and Gram-positive bacteria. Penicillin solution is sensitive to temperature and pH, easy to degrade at room temperature, and needs cryopreservation, the stability of penicillin solution is the most stable when pH is 6.0-6.5. Streptomycin was relatively stable, and pH 5.0-7.5 was the most stable, while neomycin sulfate is more stable.