By Levi Clancy for Student Reader on

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An antibiotic is any chemical which inhibits microbial growth.

Bleach is an antibiotic which completely sterilizes any surface it touches. However, there are other antibiotics which only affect certain cell types. These are useful for isolating bacteria, fungi and subtypes thereof. To test for antibiotic secretion, the microbe of interest is plated onto a lawn of cells. If clearings form around plated colonies, then antibiotics are secreted; if there are no clearings, then antibiotics are likely not secreted. Commonly used antibiotics are described below.



Cycloheximide selectively inhibits eukaryotes by interfering with 80S ribosome-directed protein synthesis.


Chloramphenicol selectively inhibits prokaryotes by interfering with 70S ribosome-directed protein synthesis.