Cycloheximide is a naturally occurring fungicide produced by the bacterium Streptomyces griseus. Cycloheximide exerts its effects by interfering with the translocation step in protein synthesis (movement of two tRNA molecules and mRNA in relation to the ribosome), thus blocking eukaryotic translational elongation.

What is the purpose of the cycloheximide in the plates?

Cycloheximide is used in a variety of media for the isolation of pathogenic fungi to inhibit certain non-pathogenic fungi like saprophytic moulds and yeasts. It is especially useful in the isolation of dermatophytes.

How do you use cycloheximide?

Directions for Use: Cycloheximide is supplied as a lyophilized powder. For a 10 mg/ml stock, carefully weigh out and reconstitute 50 mg in 5 ml DMSO or EtOH. Working concentrations and length of treatments vary depending on the desired effect, but it is typically used at 5-50 µg/ml for 4-24 hours.