Ringer's solution is the name given to a solution of several salts dissolved in water for the purpose of creating an isotonic solution  relative to the bodily fluids of an animal. Ringer's solution typically contains sodium chloride

Sodium chloride

Sodium chloride, also known as salt, common salt, table salt or halite, is an inorganic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms...

, potassium chloride

Potassium chloride

The chemical compound potassium chloride is a metal halide salt composed of potassium and chlorine. In its pure state, it is odorless and has a white or colorless vitreous crystal appearance, with a crystal structure that cleaves easily in three directions. Potassium chloride crystals are...

, calcium chloride

Calcium chloride

Calcium chloride, CaCl2, is a salt of calcium and chlorine. It behaves as a typical ionic halide, and is solid at room temperature. Common applications include brine for refrigeration plants, ice and dust control on roads, and desiccation...

 and sodium bicarbonate

Sodium bicarbonate

Sodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula Na HCO3. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda . The natural mineral form is...

, with the latter used to balance the pH

PH

In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...

. Other additions can include chemical fuel sources for cells, including ATP

Adenosine triphosphate

Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...

 and dextrose, as well as antibiotics and antifungals.

To produce a standard isotonic solution 6.5g NaCl, 0.42g KCl, 0.25g CaCl2 and 1 mole of Sodium bicarbonate is dissolved in one litre of distilled water.

Ringer's solution is frequently used in in vitro experiments on organs or tissues, such as in vitro muscle testing

In vitro muscle testing

In vitro muscle testing is a method used to characterize properties of living muscle tissue after having removed the tissue from an organism. This allows more extensive and precise quantification of muscle properties than in vivo testing...

. The precise mix of ions can vary depending upon the taxon, with different recipes for birds, mammals, freshwater fish, marine fish, etc. It may also be used for therapeutic purposes, such as arthroscopic lavage

Arthroscopic lavage

"Lavage" means 'washing'. To lavage a joint means to wash out any blood, fluid or loose debris from inside the joint space.Arthroscopic lavage is generally combined with arthroscopic debridement, where fronds of joint material or degenerative tissue are removed using a combination of injected fluid...

 in the case of septic arthritis

Septic arthritis

Septic arthritis is the purulent invasion of a joint by an infectious agent which produces arthritis. People with artificial joints are more at risk than the general population but have slightly different symptoms, are infected with different organisms and require different treatment. Septic...

.

Ringer's solution is named after Sydney Ringer

Sydney Ringer

Sydney Ringer FRS was a British clinician and pharmacologist, best known for inventing Ringer's solution. He was born in March 1836 in Norwich, England and died following a stroke 14 October 1910, in Lastingham, Yorkshire, England...

 in 1882, who found out that solution perfusing a frog's heart must contain sodium, potassium and calcium salts in a definite proportion if it has to beat for long. Ringer's solution is frequently used in human medicine in the form of Lactated Ringer's solution

Lactated Ringer's solution

Lactated Ringer's solution is a solution that is isotonic with blood and intended for intravenous administration. It may also be given subcutaneously....

.