Agar itself does not contain nutrients, will not affect the experimental material due to its own nutrients, after all, in order to ensure the synchronization of the experimental environment, to prevent unforeseen factors affect the results. Because some experiments require the material to be in a solid matrix, and agar has good solidifying properties, agar is used in many experiments in biology.

This is the same as vermiculite in plant growing, which only serves as a fixative.