Cycloheximide can be used as an experimental tool in molecular biology to determine the half-life of a
protein. Treating cells with cycloheximide in a time-course experiment followed by
western blotting of the cell lysates for the protein of interest can show differences in protein half-life. Cycloheximide treatment provides the ability to observe the half-life of a protein without confounding contributions from transcription or translation. Irreversible analogues of cycloheximide have also been reported. Mitochondrial protein synthesis is resistant to inhibition by cycloheximide. On the other hand chloramphenicol inhibits mitochondrial (and bacterial) protein synthesis, but synthesis on cytoplasmic ribosomes is resistant. Before genomes were available, these inhibitors were used to determine which mitochondrial proteins were synthesized in the mitochondria from mitochondrial genes. Cycloheximide is used as a plant growth regulator to stimulate ethylene production. It is used as a rodenticide and other animal pesticide. It is also used in media to detect unwanted bacteria in beer fermentation by suppressing yeasts and molds growth in test medium. The translational elongation freezing properties of cycloheximide are also used for ribosome profiling / translational profiling. Translation is halted via the addition of cycloheximide, and the DNA/RNA in the cell is then nuclease treated. The ribosome-bound parts of RNA can then be sequenced. Cycloheximide has also been used to make isolation of bacteria from environmental samples easier. ==Spectrum of fungal susceptibility==