Agar

Agar is a substance jelly-like jelly made from from red algae. It consists of agarose and a mixture of molecules known as agaropectin.

You can grow bacteria on agar plates: that is how bacteria are laid out for testing in hospital pathology departments. It is used as a place to grow bacteria in an microbiology laboratory.^[1]

Domestically, it is used to make desserts, as a laxative, and in the process of brewing.

The word "agar" comes from the Malay word agar-agar, a word which is used for "red algae", where the jelly comes from.^[2]

1. ↑ Smith A. 2005. History of the Agar Plate. Laboratory News. [1] Archived 2012-10-14 at the Wayback Machine
2. ↑ "Training Manual on Gracilaria Culture and Seaweed Processing in China". www.fao.org. Retrieved 2021-03-24.