Can I clean polypropylene tube with 70% ethanol and MilliQ water? - (Nov/09/2015 )

The polypropylene microcentrifuge tube is manufactured by USA Scientific. It was used to store a stock solution with no bacterial contamination. I want to reuse the tube for the same solution. Can I clean it with 70% ethanol and rinse it several times with MilliQ water? Can I skip the ethanol and just directly rinse with MilliQ water? Thank you in advance for the answers.

Should be fine. There may be some dilution of your sample if you fail to dry the tube fully. It's hard to believe this is cost effective, however.

I don't see how it's worth it. Add the cost of the MilliQ water, the 70% ethanol (made with MilliQ water, of course) and your time spent - those things are worth more than the few cents each tube cost. Worst of all is the risk of contamination of your stock and potential damage to your downstream experiments. 

I try to reuse many "one use" or "disposable" items in lab as well...but microcentrifuge tubes?  Eppendorfs?  Not really worth it...however if you are storing the SAME solution in the tube I don't see any significant risk of contamination.

I believe polypropylene tubes are OK to autoclave (but double check the specs first for your tube).

In any case, I usually reuse non-glass containers by cleaning with 10% bleach (to kill bacteria), then ethanol, then drying in oven till no bleach smell is detected.  

Although there is a lot of waste in lab, sometimes you just gotta let somethings go..

Do you want to  aliquot your solution? If not, that's not worth to do it. Something could reuse in lab, some containers (including tubes) I used for cell experiment, could be washed and autoclave sterilized, and then be used for bacterial culture or experiments outside the cell room.