syringe filter misconceptions

[nandi12]

I originally posted this over at Triedia, but it seems enough members here either make their own tren or are interested in doing so I thought it worthwhile to post here also.

No doubt some will take issue with this post, but I have seen a number of misconceptions in posts on this site
regarding syringe filters that I think need to be addressed.
First and most important is that 0.45 micron filters are not intended by their manufacturers for sterilization. 0.22
microns is considered the maximum acceptable pore diameter for this purpose. Visit the Corning website for more
info:

http://www.corning.com/LifeSciences...tration.asp#5.7

Secondly, the common glass microfiber or GD/X filter is not resistant to benzyl alcohol. Nylon is a much better
choice. Check the table of chemical compatibilities at the Pall Corp. website to see if the membrane you intend to
use is resistant to benzyl alcohol:

http://www.pall.com/catalogs/filter...hem_compat2.asp

Glass is particularly unsuitable for sterilization since it has the greatest range in pore diameters of any material.
Remember that the stated pore diameter is only an average. With glass there are many more pores with diameters
greater than the stated average than with any other membrane material.

Lastly, filter manufacturers recommend using a 10ml syringe since with anything smaller, pressures can develop
that exceed the threshold of a given membrane.

 

[Zyglamail]

While that is all fine and dandy and good to know keep in mind that even though your ran a product through a .22 filter doesnt mean you will have a sterile product for long, glass vial or not. I dont know about everyone else, but most people inject air into the vial prior to drawing, which means anything airborne will be injected into the vial. I for one think a .22 is unnecessary, after all, like I said your injecting airborne particulates back into the vial anyways and in turn into you arse.

 

[panerai]

So far, I havn't heard of single infection from home made Fina.

 

[nandi12]

It is estimated that 80% of abscesses are caused by Staphylococci, which reside on the skin and other surfaces and are not typically airborne. The liklihood of introducing these bacteria in significant numbers when reusing a vial is minimal, unless the septum is not cleaned with alcohol. I am much more concerned with potentially large concentrations of Staph or more exotic bacteria that may have contaminated the pellets during their manufacture, and which a 0.45 micron filter will not remove. When filter manufacturers specifically state that 0.45 micron filters are not intended for sterilization, I can see no justification for their use. The peace of mind knowing that I did everything I could to minimize contamination is worth the little bit of extra time involved using a finer filter.

 

[genarr3]

Good post nandi12

 

[nikolai_bolkov]

So just bake it to be sure.

Good post though since I just got done filtering with .45 with a warm fuzzy feeling that it was clean...

 

[Your_Moms_Kneepads]

Good post nandi12

I'll second this...again, great post.