Whatman glass vacuum filter sterilization

[slammingsteel68]

I have seen many posts about using this setup rather than using the standard syringe filters. What I haven't seen is any posts on how to sterilize the stone filter prior to use. Would it be the same as sterilizing vials? Not trying to start a sterilizing argument here. Would just like to know how you guys that are already using them are cleaning them and the steps involved. Any advice would be great thanks

 

[master.on]

I have seen many posts about using this setup rather than using the standard syringe filters. What I haven't seen is any posts on how to sterilize the stone filter prior to use. Would it be the same as sterilizing vials? Not trying to start a sterilizing argument here. Would just like to know how you guys that are already using them are cleaning them and the steps involved. Any advice would be great thanks

Could you please clarify what do you mean by STONE filters?

 

[slammingsteel68]

Sure. The white part that you put the .22 filter on then the funnel on top of that. We use them at work and refer to them as porous stone filter. Sorry about that.

 

[slammingsteel68]

Hope the pic helps

 

[master.on]

Sure. The white part that you put the .22 filter on then the funnel on top of that. We use them at work and refer to them as porous stone filter. Sorry about that.

Is that a PREfilter?
I mean is that before/above the 0.22 filter?
if it does then it doesn't need to be sterilized.
You can even use some coffee filter as PREfilters, they just remove particulate matter to avoid clogging the 0.22 filter.

If it's AFTER the 0.22 filter
then just don't
don't use anything after the 0.22 filter. If possible have the syringe needle pouring directly in sterile vials.

filter to needle to sterile vial
nothing else in-between

 

[master.on]

Hope the pic helps

That doesn't fit the SYRINGE filter, does it?

At this point I'm confused on what you're trying to do
you mention both syringe filters and vacuum
it's one or the other, not both
please clarify.

 

[Rockclimber]

All of mine come sterilized from the factory. Are you reusing them or something?

 

[slammingsteel68]

With filter on

 

[slammingsteel68]

With filter under funnel

 

[slammingsteel68]

It's a full glass set up. The only part you throw away is the 44mm pvdf filter.

 

[master.on]

With filter on

With filter under funnel

It's a full glass set up. The only part you throw away is the 44mm pvdf filter.

Everything after/below the filter should be sterile.

What worries me is that it looks like a Buchner funnel
Büchner funnel - Wikipedia
where only vacuum keeps the filter membrane in place
and oil can leak below the membrane passing unfiltered.

Nothing wrong with reusable filters where you only replace the membrane
in fact that's what big pharma does,
but at least get pharma filter housings (usually stainless steel) where RUBBER GASKETS/O-RINGS keep the membrane in place.
Usually they screw open to replace the membrane

like these

Having oil passing unfiltered without you even realizing it sounds SCARY to me.


The trouble with Buchner funnels
It works ok some of the time but these things leak often.
The liquid goes under the filter paper at times. I have to filter over and over again until by pure chance it works.
Sciencemadness Discussion Board - The trouble with Buchner funnels - Powered by XMB 1.9.11

 

[slammingsteel68]

Exactly why I am asking on this forum.
There is a clamp that holds the funnel in place no leak by. Buchner set up is the same thing different name / manufacturer . Probably should have went with that first. Sorry for the confusion.

 

[master.on]

Exactly why I am asking on this forum.
There is a clamp that holds the funnel in place no leak by. Buchner set up is the same thing different name / manufacturer . Probably should have went with that first. Sorry for the confusion.

Yeah, but what holds the filter MEMBRANE in place?
just vacuum?

If so, it can fail and oil leak beneath the filter.
IMO too much if your health is at risk.

 

[slammingsteel68]

Guess I'll be looking for a different filter set up...
Thought this might work but I see what you're saying. Thanks

 

[Digger]

Pretty sure there's guys over at asf that use that setup. Be careful handling that filter paper tho. There are YouTube videos on how to operate it.

 

[master.on]

Guess I'll be looking for a different filter set up...
Thought this might work but I see what you're saying. Thanks

At least try to see if you can get steel housings that SECURELY hold the filter membranes you have at hand.
If you find them, you'll save a lot in the long run.

Again, that's what big pharma does.

 

[slammingsteel68]

I use them at work doing industrial chemistry so using them not a problem. Ensuring that everything is clean is my ocd issue lol. Tired of loosing money to bunk or underdosed gear so I thought I would give brewing a shot. Late 40s working swing shifts got me started with hrt and has grown from there.

 

[mdhx3]

Those filters work really well. Actually, the image on one of the popular source websites shows their brewers using the exact same type. It is also what I am using. The ground glass joint on the bottom of the funnel and the top of the filter holder is what makes the seal. Mine are 47mm though; but I would assume 44mm membranes are available. Just be sure there is none of the white fritted glass is visible outside the membrane.
Also make sure your flask has vacuum before adding your product. This will prevent the membrane from floating and allowing material under the membrane.
I ordered all sterile filters. They cost about twice as much, but I imagined contaminants from the bottom side of an unsterile filter being drawn into my finished product. It stands to reason that microorganisms could be on both sides of anything unsterile; so you could inadvertently introduce bacteria into your oil even if you did everything else perfectly.

I used some connections in my business to test my stuff for sterility be injecting some into aerobic, anaerobic, and AFB blood culture vials. All of the stuff I made with these filters is completely sterile. I was paranoid about even using AAS; and even more paranoid about screwing it up.
Just be super Type-A about your cleanliness and sterile field.
As a species, we have created bacteria that are next to impossible to kill. Years of people not finishing antibiotic prescriptions and antibiotic overprescribing have made some nasty bugs.

 

[mdhx3]

Also, practice with them by just filtering some oil a couple times before you brew. You don't risk any money waste that way. I had used these for years in the past; but never with concern for sterility. You will be surprised how many times you will need to touch something sterile with your dirty hands if you don't have a "system" planned out before you start.
Good luck.

 

[mdhx3]

And, sorry, I just realized your post was about sterilizing the filters.
I use an autoclave to sterilize after washing with Alconox.
Others here wash, rinse with distilled water, rinse with isopropanol, again with distilled water, and bake to sterilize glassware. That is a great alternative to the autoclave; and the filter glassware is no different than other glassware.