Water - deionized or distilled (Jul/10/2006 )

Stupid question :

What´s the difference between deionized water and distilled water?
When do we use each?

Thanks

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hi biope !
deionised water is prepared by ion exchange process. cations and anions are removed by anion exchanger and anionexchanger. while distilled water is prepared by evaporation of water and then condensation. water evaporates while leaving the ions. more the no of times it is evaporated pure the water is. so both the water is devoid of ions but named after the process.
the conductivity of pure water should be around zero.

cheers

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My experience is that distilled water is usually good enough for e.g. PCR reactions. I know some people use deionized water for pcr products to be sequenced, but being a novice, I dont really know if it makes much of a difference.

excerpt from wikipedia.org:

Distilled water is water that has had virtually all of its impurities removed through distillation (boiling the water and re-condensing the steam into liquid water in a clean container, thus leaving contaminants behind).

Deionized water is water that lacks ions, such as cations from sodium, calcium, iron, copper and anions such as chloride and bromide. This means it has been purified from all other ions but H3O+ and OH−, but it may still contain other non-ionic types of impurities such as organic compounds. This type of water is produced using an ion exchange process.

Deionized water is similar to distilled water, in that it is useful for scientific experiments where the presence of impurities may be undesirable.

The uses of ultrapure deionized water are many and varied, often having application in scientific experimentation such as when very pure chemical reaget solutions are needed in a chemical reaction or when a biological growth medium needs to be sterile and very pure.

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Take care!

In our lab we´re using deionized water and double distilled water.
A lot of pyrogenic organic compounds remain in deionized water, therefore you need a activated-carbon filter behin the ionexchange cardridge, also a UV-lamp degrade these contaminents.
In distilled water there also left some nice friends. A lot of chemicals form an azeotrope, a mixture of two liquids that has a constant boiling point and composition throughout distillation. Than you have the same impurity in your distilled water...(like ethanol or benzene)

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