difference between distilled water and deionized water - (Oct/16/2005 )
Here's another thought: is distilled water even available any more? I've never seen nor heard of anyone having a distiller. MilliQ seems to be the standard, and it's just as good (if not better).
you don't need air for the organism to grow. some are anaerobic and there may be enough dissolved gasses for others. but, keep in mind that your tubing was dry at one time. did you sterilize the tubing immediately prior to filling it with water?
some labs still use stills, it is cheaper to operate. it depends on their requirements.
Which water do you use for PCR reaction?.
MiliQ water? isnt it standard?
Here's another thought: is distilled water even available any more? I've never seen nor heard of anyone having a distiller. MilliQ seems to be the standard, and it's just as good (if not better).
you don't need air for the organism to grow. some are anaerobic and there may be enough dissolved gasses for others. but, keep in mind that your tubing was dry at one time. did you sterilize the tubing immediately prior to filling it with water?
some labs still use stills, it is cheaper to operate. it depends on their requirements.
While some organisms don't need air to grow they do need nutrients which would be lacking in a MilliQ tube. Also the MilliQ water entering the tube would be rather hypo-osmotic and probably cause any cells in it to burst. Has anyone here actually plated MilliQ water to see if it has anything growing in it?
Jeff
is there any difference in price between these water types!? 
Here's another thought: is distilled water even available any more? I've never seen nor heard of anyone having a distiller. MilliQ seems to be the standard, and it's just as good (if not better).
you don't need air for the organism to grow. some are anaerobic and there may be enough dissolved gasses for others. but, keep in mind that your tubing was dry at one time. did you sterilize the tubing immediately prior to filling it with water?
some labs still use stills, it is cheaper to operate. it depends on their requirements.
While some organisms don't need air to grow they do need nutrients which would be lacking in a MilliQ tube. Also the MilliQ water entering the tube would be rather hypo-osmotic and probably cause any cells in it to burst. Has anyone here actually plated MilliQ water to see if it has anything growing in it?
Jeff
Even if the final filter is a 0.2 micron sterile filter and the receiving vessel sterilized, I don't think that it could be considered formally sterile. I agree with what was said above, that any tubing post-filter is at considerable risk to have some kind of biofilm or fungus unless kept under a biohazard hood. Strict lab policy would dictate that anything sterile and sealed, once opened in a non-sterile environment, cannot be considered sterile anymore. For example, a bottle of autoclaved water, or a box of tips, if opened at the bench rather than under a sterile hood. For practical purposes though, the potential contamination is likely very low, and any potential problem depends entirely upon the subsequent techniques.
Millipore water should still be autoclaved or sterile filtered (0.22 um). If there's any traces of bacteria, of course, there could be endotoxins. So for endotoxin-free water, we use something like Baxter sterile water.
PCR can be performed using distilled, deionized or MilliQ water without issues. I recommend autoclaving too since it will kill any bugs that may be floating around. When running a PCR, it's important to use DNase-free water. Autoclaving water will denature any trace DNase. If you are handling RNA, it's extremely important to use RNase-free water. RNase will NOT be inactivated by autoclaving.
Amazing ignorance.
DI water is NOT the same as distilled - double or not. Not only are the processes to produce different - the waters themseves are different.
AND MilliQ water is NOT sterile when it comes out of the "machine". That is also bull. It is merely an ion exchnage process. THink!!! WHY would you think it sterile?
MilliQ water is NOT sterile.
Appl Environ Microbiol. 1993 May;59(5):1410-5. Links
Distribution of bacteria within operating laboratory water purification systems.McFeters GA, Broadaway SC, Pyle BH, Egozy Y.
Department of Microbiology, Montana State University, Bozeman 59717.
Experiments were conducted to measure communities of bacteria within operating ultrapure water treatment systems intended for laboratory use. Samples from various locations within Milli-Q Plus and Milli-Q UV Plus systems were analyzed for populations of planktonic bacteria at weekly intervals over 3 months of operation. Relatively high initial densities of planktonic bacteria (10(2) to 10(3) bacteria per ml) were seen within both units when they were challenged with source water of poor quality, although the product water continued to be acceptable with regard to bacterial numbers, resistivity, and endotoxin concentration. Under more normal operating conditions, significant differences were seen in planktonic populations throughout the systems with excellent product water quality. A great deal of variability was observed in biofilm populations analyzed from various system surfaces after 3 months of operation. The concentrations of planktonic bacteria and biofilm densities were much lower in the unit containing a UV lamp. These findings suggest that a range of microenvironmental conditions exist within purified water systems, leading to variable populations of bacteria. However, product water of excellent quality was obtained despite the bacterial communities.