Holtfreter's solution (Holtfreter's medium) is a balanced salt solution that was developed by the developmental biologist

Johannes Holtfreter Johannes Holtfreter (January 9, 1901 – November 13, 1992) was a German-American developmental biologist whose primary focus was the “organizer,” a part of the embryo essential for the development of the proper body plan. Biography Holtfr ...

for studying amphibian embryos and to reduce bacterial infections. As a specialised

aqueous solution An aqueous solution is a solution in which the solvent is water. It is mostly shown in chemical equations by appending (aq) to the relevant chemical formula. For example, a solution of table salt, or sodium chloride (NaCl), in water would ...

, it finds use in aquaria to prevent

infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable d ...

s for early stage amphibians, where it is typically mixed with soft

tap water Tap water (also known as faucet water, running water, or municipal water) is water supplied through a tap, a water dispenser valve. In many countries, tap water usually has the quality of drinking water. Tap water is commonly used for drinking, ...

. Amphibians such as

axolotl The axolotl (; from nci, āxōlōtl ), ''Ambystoma mexicanum'', is a paedomorphic salamander closely related to the tiger salamander. Axolotls are unusual among amphibians in that they reach adulthood without undergoing metamorphosis. Inst ...

s prefer a

hard water Hard water is water that has high mineral content (in contrast with "soft water"). Hard water is formed when water percolates through deposits of limestone, chalk or gypsum, which are largely made up of calcium and magnesium carbonates, bicarbo ...

solution.

Composition

Molarity Molar concentration (also called molarity, amount concentration or substance concentration) is a measure of the concentration of a chemical species, in particular of a solute in a solution, in terms of amount of substance per unit volume of solu ...

of the component salts are as follows:

Notes

* https://www.msu.edu/user/eisthen/lab/methods/animalcare/holtfr.html ink now dead

References

* Armstrong, J.B., Duhon, S.T., and Malacinski, G.M. (1989) "Raising the axolotl in captivity". In J. B. Armstrong and G. M. Malacinski (eds.) ''Developmental Biology of the Axolotl''. New York: Oxford University Press, pp. 220–227. Solutions Antimicrobials {{chemistry-stub