- Amphotericin B is an antifungal agent widely used in cell culture to prevent contamination by fungi, including both yeasts and filamentous molds. It is particularly effective against fungal species like Candida, Aspergillus, and Cryptococcus.
- Amphotericin B acts by binding to ergosterol, a key component of fungal cell membranes, forming pores that disrupt membrane integrity. This causes leakage of intracellular contents and ultimately cell death. Because ergosterol is unique to fungi (not found in mammalian cells), Amphotericin B has selective toxicity, making it a valuable tool in maintaining sterility in eukaryotic cell cultures.
- In cell culture, Amphotericin B is commonly used at concentrations ranging from 0.25 to 2.5 µg/mL, often as part of an antibiotic-antimycotic mixture that includes penicillin and streptomycin. While effective at controlling fungal growth, Amphotericin B is also known for its potential cytotoxic effects on mammalian cells. Though mammalian cell membranes contain cholesterol instead of ergosterol, Amphotericin B can still interact weakly with cholesterol-containing membranes, especially at higher concentrations or with prolonged exposure. This can lead to increased membrane permeability, oxidative stress, or even cytotoxicity in sensitive cell lines.
- Because of these potential side effects, Amphotericin B should be used only when fungal contamination is a significant risk, such as during the early culture of primary tissues or in non-sterile environments. Routine use in long-term cultures is discouraged unless absolutely necessary. To minimize adverse effects, some labs opt for Liposomal Amphotericin B, a formulation with improved selectivity and reduced cytotoxicity, though it is more expensive.
