CHU 13 medium is a

culture medium A growth medium or culture medium is a solid, liquid, or semi-solid designed to support the growth of a population of microorganisms or cells via the process of cell proliferation or small plants like the moss '' Physcomitrella patens''. Diffe ...

used in

microbiology Microbiology () is the branches of science, scientific study of microorganisms, those being of unicellular organism, unicellular (single-celled), multicellular organism, multicellular (consisting of complex cells), or non-cellular life, acellula ...

for the growth of certain

algal Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, s ...

species, first published by S.P. Chu in 1942. It is used as growth medium for the

biofuel Biofuel is a fuel that is produced over a short time span from Biomass (energy), biomass, rather than by the very slow natural processes involved in the formation of fossil fuels such as oil. Biofuel can be produced from plants or from agricu ...

candidate alga ''

Botryococcus braunii ''Botryococcus braunii'' is a green, pyramid-shaped planktonic microalga that is of potentially great importance in the field of biotechnology. Until 2024 it was considered to have three races: A, B, and L., but it was then determined that these ...

''.C. Largeau, E. Casadevall, C. Berkaloff and P. Dhamelincout (1980) Phytochemistry, 19, 1943. Botryococcus braunii

CHU 13 includes essential

minerals In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): M ...

and trace elements that are required by algae for growth, but does not include a carbon source and so is only appropriate for growth of

phototroph Phototrophs () are organisms that carry out photon capture to produce complex organic compounds (e.g. carbohydrates) and acquire energy. They use the energy from light to carry out various cellular metabolic processes. It is a list of common m ...

s. It can be prepared as either a liquid medium or as an

agar Agar ( or ), or agar-agar, is a jelly-like substance consisting of polysaccharides obtained from the cell walls of some species of red algae, primarily from " ogonori" and " tengusa". As found in nature, agar is a mixture of two components, t ...

medium. The remaining volume is pure, de-ionized water. Because it is difficult to weigh out some of the trace minerals, it is advisable to create a mixture of all components at a large concentration, such as a thousand times these measures, and then mix with the appropriate amount of (pure, de-ionized) water. Correct pH to 7.5, and then autoclave.

References

Microbiological media Algaculture {{Microbiology-stub