OK, I have some of the stealth gear. I was wanting to be on the safe side and filter it. I was going to buy a sterile 20ml vial(i have 4 5ml sachets)and a .45 whatman filter and filter it. Would it be best to put the filter on one syringe and draw the contents from all 4 of the packs with the same syringe and inject into the vial?? How exactly does the filter work? Seems like it would catch particles on one side of the filter when drawing contents and then those particles would be on that side when you inject the contents into the vial making it where the particles could be released? I guess I am asking what the best way to do this would be????