Ringer's solution is a special salt solution made up to be isotonic to physiological pH. It is named for Sydney Ringer, who determined that the liquid around a frog's heart must contain a set proportion of salts if the heart is to remain to beat (1882 -1885). There are different recipes for Ringer's solution, depending on its intended purpose and the organism. Ringer's solution is an aqueous solution of sodium, potassium and calcium salts. Lactated Ringer's solution (LR, LRS or RL) is a special Ringer's solution that contains lactate and is isotonic to human blood. Here are some recipes for Ringer's solution.
Ringer's Solution pH 7.3-7.4
- 7.2 g sodium chloride - NaCl
- 0.37 g potassium chloride - KCl
- 0.17 g calcium chloride - CaCl2
- Dissolve the reagents into the reagent-grade water.
- Add water to bring the final volume to 1 L.
- Adjust the pH to 7.3-7.4.
- Filter the solution through a 0.22-μm filter.
- Autoclave Ringer's solution prior to use.
Emergency Veterinary Ringer's Solution
This solution is intended for rehydration of small mammals, to be administered orally or subcutaneously via a syringe. This particular recipe is one that can be prepared using common chemicals and household equipment. Reagent-grade chemicals and an autoclave would be preferable if you have access to those, but this gives you an idea of an alternate method of preparing a sterile solution:
- 9.0 g sodium chloride - NaCl (154.00 mM): non-iodized table salt
- 0.4 g potassium chloride - KCl (5.64 mM): Morton or NOW salt substitute
- 0.2 - 0.3 g calcium chloride - CaCl2 (2.16 mM): calcium chloride powder
- 1.3 g dextrose (11.10 mM): granular dextrose
- 0.2 g sodium bicarbonate - NaHCO3 (2.38 mM): baking soda (*add last)
- Mix together the sodium chloride, potassium chloride, calcium chloride and dextrose solutions or salts.
- If salts were used, dissolve them in about 800 ml of distilled or reverse osmosis water (not tap water or spring water or water to which minerals have been added).
- Mix in the baking soda. The baking soda is added last so that the calcium chloride will dissolve/not precipitate out of solution.
- Dilute the solution to make 1 L of Ringer's solution.
- Seal the solution in small canning jars and cook it at least 20 minutes in a pressurized steam canner.
- The sterile solution is good for 2-3 years unopened or up to 1 week refrigerated, once opened.
Biological Bulletin Compendia, Cold Spring Harbor Protocols