Sciencemadness Discussion Board

Reusing disposable bottle top filters - with new filter paper??

RogueRose - 29-5-2017 at 09:52

I'm wondering if anyone has ever tried to reuse the physical structure of these bottle top filters (vacuum).



I haven't removed the filter paper from one yet but I can see on one that I have there looks to be ridges under the paper - which allow the flow of the liquid and keep the paper off the bottom of the filter/funnel. There is about 1/8"+ of a ring around the outside of the filter to allow for another piece of filter to be placed on top and get a decent seal - especially once wetted.

Anyway, just thought that these might be worth looking at if someone has one and may be able to re-use it with a new filter pad/piece.

UC235 - 29-5-2017 at 10:02

These are 0.22um pore size filters. They're disposable, sterilized, and intended for media prep in biology/biochemistry to filter bacteria out of whatever you run through them, then discard. The plastic is usually brittle polystyrene and I imagine they plug immediately with any sort of real particulate.

RogueRose - 29-5-2017 at 11:23

Quote: Originally posted by UC235  
These are 0.22um pore size filters. They're disposable, sterilized, and intended for media prep in biology/biochemistry to filter bacteria out of whatever you run through them, then discard. The plastic is usually brittle polystyrene and I imagine they plug immediately with any sort of real particulate.


yeah, that is what is in the picture - there is a wide range of pore sizes - I just picked an image to show the general idea, not exact item. I know what the intended use is but the ones I have look like the filter paper would peel off (it's glued around the edge but seem loose towards the center). I figured the paper would be removed after it is used and replaced with another paper (not glued). I've never used a buchner funnel but this seems similar in some aspects (allows for paper to sit off bottom).

As far as being brittle, well, that be the case with anything that is filtered through this - know what not to filter..

tshirtdr1 - 29-5-2017 at 16:11

I use a plastic buchner funnel that comes apart in 2 pieces so it is easy to clean. About $20 and lasts for years.

Dr.Bob - 29-5-2017 at 18:21

Jut buy a glass membrane filter holder. They are designed to use disposable filters and can be reused. You can use fancy membrane filters or even just paper filters. I have a box full of them, so I am happy to beat any price on Ebay.

One example is below, I have a variety of them available, most of mine are just designed for a filter funnel with a simple stopper.

http://www.ebay.com/itm/250-5000ML-Membrane-Glass-Filter-App...