Do you actually need a vent needle when filtering into a 5mL sterile vial?
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Been going back and forth on this for weeks and want to hear from people who actually filter.
My setup: reconstitute in the original vial (0.5-2mL bac water depending on the peptide), draw the full contents into a 3mL Luer Lock syringe, attach a 13mm PES 0.22um filter, attach a fresh 21G on the output side, push through into a sealed 5mL sterile receiving vial (ALK).
My biggest transfer is about 2.15mL into a 5mL vial. That is less than half the vial's air space.
I keep seeing people say you need a vent needle in the receiving vial to let displaced air escape while you push liquid in. Some people use a plain 18G, some say you need a filtered 0.2um hydrophobic vent, and those things are either impossible to source as an individual or cost $300+ each.
But if I am only pushing ~2mL into a 5mL vial, is the back-pressure actually a problem? It seems like the air just compresses a bit and the syringe plunger handles it fine. Has anyone here actually tried filtering into a sealed 5mL vial without any vent at all?
If you do use a vent, are you using a plain open needle or a filtered one? And if plain, does that not defeat the entire purpose of filtering since you just gave room air a direct path into the vial you are trying to keep clean?
Genuinely trying to figure out the right move here.Appreciate any real experience.
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My experience. Your empty vial should be under vacuum, from being sterilized, and will pull your liquid in. If you hit a stopping point pull back on syringe and finish your push. Repeat pull and push as needed.
I only vent on pen vials. Adding a filter to your vent is a personal choice, some do some don’t. You filter the peptide because sterility is often unknown. -
@myb this! The primary context I see vent needles being used is for loading pen cartridges, where they are pressure neutral and filling the Cartridge without a vent may (will?) push the plug out. When I am moving peps from one vial to another, I do not vent.
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@myb this! The primary context I see vent needles being used is for loading pen cartridges, where they are pressure neutral and filling the Cartridge without a vent may (will?) push the plug out. When I am moving peps from one vial to another, I do not vent.
@ResearchCat
Ahhh - can in fact confirm that attempting to fill a pen cartridge with 2.5ml of BAC & 30mg of RETA without a vent needle will in fact eject the plug like a pop gun and spray the liquid all over one’s own fat guts.
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@statieeight
laughing with you, not at you. I haven’t had that happen, but I have blown over the vent and spilled SS-31 all over my hands and desk.I did not expect reconstituted peptides to be so, well, sticky. what a mess!
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@ResearchCat
Ahhh - can in fact confirm that attempting to fill a pen cartridge with 2.5ml of BAC & 30mg of RETA without a vent needle will in fact eject the plug like a pop gun and spray the liquid all over one’s own fat guts.@STATIEEIGHT said in Do you actually need a vent needle when filtering into a 5mL sterile vial?:
@ResearchCat
Ahhh - can in fact confirm that attempting to fill a pen cartridge with 2.5ml of BAC & 30mg of RETA without a vent needle will in fact eject the plug like a pop gun and spray the liquid all over one’s own fat guts.Lol. I sacrificed a cartridge for my first time filling one using tap water so I can practice. Good thing I did. Totally forgot the vent needle and sure enough it popped out.
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This post is deleted!
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I am wondering if anyone has had an issue with the breather needle leaking peptide while filtering? Everything was going fine until the last .5ml. I was pushing in slowly like usual, but all of the sudden peptide bubbled up out of the breather needle.
@kmckinley
You’ve got to keep the tip of the breather needle above the level of the liquid. -
Yeah, I have had an overflow before. Part of the learning process. Also note that depending on how many vials you are trying to combine into one cart, you might end up with more liquid than will fit in the cart, no matter how convinced you are that you can make it happen.
(looks in the mirror in NAD+)
