When you think of water, you might think of the water that comes out of your tap or maybe the bottled water you grab from the store. But when it comes to scientific research and medical purposes, you don't want to use just any water source. You need sterile water.   Sterile water is free of microorganisms such as bacteria, fungi, and spores. It is used for medical research and irrigation purposes to avoid the risk of contamination present with regular water. In medical research, normal water cannot be used as the microorganisms contained in non-sterile water can alter the results of lab research.

What's the difference between sterile water and distilled water?

Sterile water and distilled water are often confused with one another but they are not exactly the same and do not have the same uses. Distilled water is created through a process that involves condensation and steaming. There is no salt, iron, or calcium involved in the creation of distilled water. Distilled water has a wide variety of uses, including being used to clean medical tools because the lack of minerals won't cause spotting. Sterile Water for Irrigation USP is a fluid with the pH of about 5.7 and used as a solvent to dissolve or dilute drugs. Its pharmaceutical purpose is for injection of non-intravenously administered medication and nutrient mixtures, or as an irrigating fluid. It is prepared by distillation and contains no bacteriostatic or antimicrobial agents or added buffers. Because Sterile Water for Irrigation USP is hypotonic, it is not used during surgical procedures because it causes hemolysis (the destruction of red blood cells) and is absorbed readily by the tissues.  

Does boiling water create sterile water?

Boiling water for twenty minutes will remove infection causing bacteria which makes it an ideal sterilization process for drinking purposes, but it would not create sterilized water that could safely be used for medical and scientific research purposes. Boiling water is just one step of the sterile water creation process.  

How to make sterile water

It is possible to make your own sterile water if you have the patience and supplies needed. If you do decide to make your own, remember to store in a sterilized container in a cool location out of direct sunlight.  To sterilize your container, you can put it in boiling water for 10 minutes.   You will need:
  • Pressure cooker or hermetically sealed pot
  • Filtered water
  • Stove
  • Thermometer
  1. Fill the pressure cooker with water.
  2. Place cooker on stove and boil for at least 20 minutes.
  3. Maintain temperature within the cooker at 250 degrees Fahrenheit throughout the boiling period. This is what sterilizes the water rather than just having boiled water.
  Now you have sterile water! It will only remain sterile as long as it is saved in sterilized containers that are also free from contaminates. It is best to use the (cooled) sterile water immediately to ensure it is contaminate-free, but under the right conditions it can be preserve for up to three days.  

Where do I buy sterile water?

If not making your own sterile water, you can buy it from reputable medical and research supply companies either online or in person. At Med Lab Gear, we provide 20ml sterile water for injection in single-dose plastic, flip-top bottles for ease of use and designed to minimize the risks for contamination.