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Can you make nuclease free water or does it need to be bought in? - (Mar/02/2007 )

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Back to the original question: Can you make nuclease free water – or does it need to be bought in? ...and if so how is it made?

See the technical documents available at

We use Cole Parmer FEP convoluted tubing to replace the tygon tubing typically used to dispense water from Milli-Q-type systems. The convoluted spiral design promotes full drainage and increases tubing flexibility. This chemical-resistant fluoropolymer tubing is sold in 5-ft lengths with nonconvoluted 1"L sections at both ends for easy connections. If you use tygon tubing, you should be autoclaving it once/week to reduce mildew growth in the tubing. FEP tubing does not support the growth of mildew and can be left in plce permanently.

Never prepare DEPC-treated water from a carboy. Always draw the water directly from the Milli-Q. If anyone in your lab prepares media such as LB anywhere near a carboy, the powder will usually contaminate the pouring spout and support mildew growth in the spout. Long term use of carboys can lead to biofilms of molds or mildew coating the walls of the carboy. Mildew RNases are NOT inactivated by DEPC.


What about using Tris? This will prevent breakdown of DNA by acidity, without having EDTA in there.

Therefore, I sometimes use 1xT - 0.1xE, so TE with a 10x dilution of EDTA.


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