At-Home Peptide Filtration Techniques and Endotoxin Testing

Sounds good, if you come up with any ways to make it simpler or want to share how your kit and process worked out that could help others who find it daunting.

What's a female side? Male luer? I'd like to know too.

I was headed toward orthopedic surgery but switched to robotics and then into pharmaceutical private equity, which combined my interests in chemistry, biology, and manufacturing. I'm not an expert in any one area but I have good people to check ideas with. My aim is to learn more and share ways to keep things safe and affordable.

A 0.22 µm filter takes out microorganisms and particulates such as bacteria, yeasts, molds, spores, tiny glass or rubber bits, undissolved peptide clumps, dust, lint, salts, some mycoplasma, basically everything except viruses and toxins. Using pyrogen-free supplies lowers endotoxin risk but grey market sources may not follow the same standards. Better to filter and test so you avoid ending up in some documentary.

I always figured it comes from the plunger, especially with bigger draws over 10 units. Rushing bigger doses can pull air in, or not keeping the needle under the liquid. I draw a little headspace air first before the liquid so the final push stays clean. Keep the air near the plunger with the needle down. Does that clarify it?

I've posted a snapshot here that shows the fitting piece along with its cover, where the socket half sits leftward and the plug half sits rightward.

That's the exact question I had, which is why the high IQ workaround is to pull sterile air into the syringe so nothing gets left behind in the filter. Pre-wetting with ethanol helps saturate the medium the same way wetting hair before swimming keeps chlorine from soaking in. Not perfect but it reduces loss.

That's what I'm wondering about. Why does it matter what wets the filter at the start, or why discard whatever comes through first? Whatever you use to wet it should still be fine after passing through. Flushing afterward makes sense to recover peptide, but tossing the initial bit as if it's somehow bad sounds like an old habit without a current reason.

One side of these filters attaches to the syringe with its larger opening which functions as female. The other side features a prolonged slimmer opening designed to insert into the needle acting as male.

Whatever gets soaked into the filter stays there and gets thrown away with it. How much have you managed to keep? If you dip a sponge in liquid you've already lost some of it. I don't see how you avoid losing what the filter absorbs. Can you explain how that's possible with a hydrophilic filter big enough for 3 mL? A roasting pan doesn't soak up the roast the way a filter soaks up liquid.

If you soak a sponge in milk then flush it with water, what's left in the sponge is mostly water. You don't have to start by pushing the milk through and tossing the first part. Unless there's something specific about these filters, there's no reason to discard the initial output. The roasting pan story is just about following a rule after the original reason no longer applies.

If it's hydrophilic then yes you can. Just switch syringes fast or use a clean box to avoid contamination. I usually finish with a push of sterile air either way. I've used bigger vials before because losing volume to absorption adds up in small ones. Works well for things like NAD+ and GLOW that we use daily so the vial gets finished before expiry.

Why don't you describe exactly how you do it so others can see? The sponge and milk comparisons don't line up with how enclosed syringe filters actually work, and bac water isn't milk. What filters are you using? I don't know of any hydrophilic filter that doesn't absorb liquid, that's what the word means.

More dilute solution is one way to go. Also agree that extra steps with swapping syringes and filters increases contamination chance even in a clean space. The discard part happens when the filter itself gets thrown out, since whatever soaked in goes with it.

I don't think we're understanding each other very well, and more back and forth probably won't make a difference. Wishing you the best though.

Can't figure out the reason for jumping in just to voice opposition to that method. Anyway, good luck to you man.

That background is really interesting. The last part says a lot about priorities, especially being in pharma where plenty of people chase money. Thanks for the thread, it should help a lot of people.

It's surprising how many people inject stuff without knowing its source. I've used a local synthesis lab and even they recommend filtering. Once I moved to grey market sources for cost I started filtering and testing. It's inexpensive so there's little reason not to when quality can vary.

where or how do you do endotoxin testing? Shipping samples out gets expensive. What peptides does the local lab make?

They can work with a range of amino acids and make GLP peptides but setup costs are high for the low doses I use. I do endotoxin testing at home for low cost and quick results. I'm not aware of any labs that take shipped samples but they probably exist.

I've successfully attached slip needles to lock syringes though trying it the opposite direction never works out.

do they sell kits for that?

I wonder if something else might work instead. This has me feeling quite concerned.

I read it the same way at first and pictured squirting some out like a nurse prepping an injection. I think the point was that the priming liquid stays in the filter and gets discarded with it. If the whole batch goes through anyway, why call out a priming step? Does the priming happen with the final needle already on? The wording around waste is what confused me, like flushing a water filter and dumping the first bit. Also maybe the amounts were meant to be smaller.

I remember cramming that material past my lips without knowing whether those prep areas were sanitary at all, long before I took up shooting the bathroom powder.

thank god for age and filters

I probably didn't lay out every step clearly since I wrote it from memory rather than while doing it. Higher dilution helps reduce loss too. When I first tried it I pushed bac water with food coloring through, then more bac water, and saw color still on the outside of the disc, so whatever you prime with stays in the filter. Some people must be taking filters apart to recover material instead of tossing the whole thing. Opinions vary a lot here so I stick with what I've done for years. I learned testing from someone who actually makes peptides in a lab. There will always be people who skip filtering or testing entirely. This area is pretty unregulated.

Since you are already filtering, why not add a hydrophobic filter on a needle and syringe without the plunger so filtered air can vent into the vial while you draw out the peptide? Even small cartridge stoppers have room for two needles. I use a 25 g to filter the peptide and a 31 g to make the air vent. That is how it was done in school and it has worked for decades. Another needle costs very little. When filling several cartridges at once the vent filter can be reused if strict sterilization is followed.

I loaded a cartridge and took some pictures for demonstration. The needles shown are 23 g and there is no problem as long as the air filter stays in the headspace. The first picture shows pulling bac, the second filling the cartridge, the third expelling air, and the fourth the full cartridge.

Where do you recommend getting filters? Everywhere I have looked they are closer to a dollar or more each.

If you have any good recommendations or reviews I would like to hear them.

Thanks for spending your effort on this along with the images. I understand your point and intend to search out similar items. My current approach involves using the PES 4mm for filtration. Obtaining materials and having them delivered here in Hawaii has become quite tricky plus costly. Do you know of any place to get them? How about moving the bac water straight over into the luerlock for rinsing and so on?

From what people say everything costs more over in Hawaii. Can you reach Amazon from there? Search around for those ten-pack filters. Hope that turns out well and let me know if I should hunt for other options. Right, I prime using bac so the edges take up mostly bac. One time I tried forcing bac with a drop of food coloring across the filter then plain bac afterward and the edges still showed the color.

There may be a lot of people interested in learning how to do this. I would greatly appreciate a rundown on endotoxin testing at home.