e solution contains 10,000 units/mL penicillin and 10,000 µg/mL streptomycin. Antibiotics - Penicillin and streptomycin are effective combined antibacterial agents against Gram-positive and Gram-negative bacteria and can be used to prevent bacterial contamination of cell cultures. Originally purified from the fungus Penicillium  , penicillin works by directly interfering with bacterial cell wall synthesis and indirectly by triggering the release of enzymes that further alter the cell wall. Streptomycin was originally purified from Streptomyces griseus . Its mechanism of action is to bind to the 30S subunit of bacterial ribosomes, thereby inhibiting protein synthesis, leading to the death of sensitive bacteria.

A variety of antibiotics and antifungals are also available in powder and liquid forms.