Peptide won't pass through the filter…

[PunkN]

I'm at my wit's end. A new tirz30 batch just got mixed up. When I try to filter it, nothing will go into the syringe. Already down 4 filters, 2 luer lock syringes, and roughly 6 needles.

Totally fed up. Every search I tried was useless. What options do I haveeeeee?????

 

[randompersonrandom]

uh...if it won't go into the syringe and a filter is in the mix, that could be what's blocking you. You draw up without any filter attached. After that, attach the filter along with a new needle, then push it into the vial or cart.

 

[PunkN]

OMG. I’ve been through this process previously, and at this point I feel like a complete idiot. To be fair, my doctor is tweaking my thyroid medication, which leaves me feeling like a loon and makes it impossible to concentrate.

 

[randompersonrandom]

PunkN said:

OMG. I’ve been through this process previously, and at this point I feel like a complete idiot. To be fair, my doctor is tweaking my thyroid medication, which leaves me feeling like a loon and makes it impossible to concentrate.

No problem at all--at least your explanation of how you do things was detailed enough that spotting the odd step was a breeze!

 

[PunkN]

Since I pick things up with mnemonics, I’ll simply keep in mind that filtering is ‘exit only’.

 

[randompersonrandom]

PunkN said:

Since I pick things up with mnemonics, I’ll simply keep in mind that filtering is ‘exit only’.

So at the very least, this settles the question of "why not push the liquid through the filter and into the syringe, rather than out of it? And if we grabbed a brand new syringe, does that change anything?" The reason is that pulling the pep in would be tougher than pushing it out.

(inevitably, somebody will jump in with "The filter has to be the final thing it goes through, otherwise we won't catch every last bit of bacteria!" and my response to that is hush up, or I'm taking your lunch money, nerd)

 

[FilterOrDeath]

randompersonrandom said:

PunkN said:

Since I pick things up with mnemonics, I’ll simply keep in mind that filtering is ‘exit only’.

So at the very least, this settles the question of "why not push the liquid through the filter and into the syringe, rather than out of it? And if we grabbed a brand new syringe, does that change anything?" The reason is that pulling the pep in would be tougher than pushing it out.

(inevitably, somebody will jump in with "The filter has to be the final thing it goes through, otherwise we won't catch every last bit of bacteria!" and my response to that is hush up, or I'm taking your lunch money, nerd)

That lunch money remark cracked me up way more than it had any right to! I also wanted to break down why attempting to use the filter that direction was such a struggle. The syringe filters in our setup only work one way, so it was doing exactly what it's supposed to by stopping anyone from drawing fluid back through the filter into the syringe. For nearly all syringe filtering, sterilization included, unidirectional filters are what we want. A few specialized bidirectional syringe filters exist that can suck liquid in without trouble. But I've never found a reason to reach for one of those.

 

[randompersonrandom]

FilterOrDeath said:

randompersonrandom said:

PunkN said:

Since I pick things up with mnemonics, I’ll simply keep in mind that filtering is ‘exit only’.

So at the very least, this settles the question of "why not push the liquid through the filter and into the syringe, rather than out of it? And if we grabbed a brand new syringe, does that change anything?" The reason is that pulling the pep in would be tougher than pushing it out.

(inevitably, somebody will jump in with "The filter has to be the final thing it goes through, otherwise we won't catch every last bit of bacteria!" and my response to that is hush up, or I'm taking your lunch money, nerd)

That lunch money remark cracked me up way more than it had any right to! I also wanted to break down why attempting to use the filter that direction was such a struggle. The syringe filters in our setup only work one way, so it was doing exactly what it's supposed to by stopping anyone from drawing fluid back through the filter into the syringe. For nearly all syringe filtering, sterilization included, unidirectional filters are what we want. A few specialized bidirectional syringe filters exist that can suck liquid in without trouble. But I've never found a reason to reach for one of those.

Alright, your lunch money stays with you — that really is a fascinating point. In the back of my mind, I was thinking, "Strange that pulling with the syringe's vacuum can't draw the liquid through, yet pushing with the syringe works. I figured the vacuum would be more powerful." But it's good to learn that the issue isn't about strength at all — it's simply that material won't pass through in that direction.

 

[miss-sanne]

Same issue on my end — turned out the syringe I used was 5 ml.

Once I moved to a 2 ml one, it went smoothly thanks to the narrower diameter.

 

[Turbo-Farmer]

I had planned to pull the solution through the filter and into the syringe. After reading this, I'll probably pass on that approach. Having that option available does sound appealing, though. Still, I suspected it wouldn't work that smoothly.

The one-way aspect never crossed my mind.

Pushing on the plunger should let you use more force than pulling on it, I'd think. That's direct pressure rather than suction.

 

[miss-sanne]

Turbo-Farmer said:

I had planned to pull the solution through the filter and into the syringe. After reading this, I'll probably pass on that approach. Having that option available does sound appealing, though. Still, I suspected it wouldn't work that smoothly.

The one-way aspect never crossed my mind.

Pushing on the plunger should let you use more force than pulling on it, I'd think. That's direct pressure rather than suction.

I gave that a shot too, haha. Filtering a second time isn't necessary for me, and it wouldn't work anyway.

Now I skip filtering altogether, since every method I've tried causes a big mess from spillage.

 

[Retazempic]

randompersonrandom said:

PunkN said:

Since I pick things up with mnemonics, I’ll simply keep in mind that filtering is ‘exit only’.

So at the very least, this settles the question of "why not push the liquid through the filter and into the syringe, rather than out of it? And if we grabbed a brand new syringe, does that change anything?" The reason is that pulling the pep in would be tougher than pushing it out.

(inevitably, somebody will jump in with "The filter has to be the final thing it goes through, otherwise we won't catch every last bit of bacteria!" and my response to that is hush up, or I'm taking your lunch money, nerd)

That was my question too. Whenever I hear "filter," my mind goes straight to a coffee filter — you can flip one inside out and it still lets the coffee through.

 

[miss-sanne]

Retazempic said:

randompersonrandom said:

PunkN said:

Since I pick things up with mnemonics, I’ll simply keep in mind that filtering is ‘exit only’.

So at the very least, this settles the question of "why not push the liquid through the filter and into the syringe, rather than out of it? And if we grabbed a brand new syringe, does that change anything?" The reason is that pulling the pep in would be tougher than pushing it out.

(inevitably, somebody will jump in with "The filter has to be the final thing it goes through, otherwise we won't catch every last bit of bacteria!" and my response to that is hush up, or I'm taking your lunch money, nerd)

That was my question too. Whenever I hear "filter," my mind goes straight to a coffee filter — you can flip one inside out and it still lets the coffee through.

Using a coffee filter would simplify this whole thing so much! Filtering is the worst lol

 

[Turbo-Farmer]

miss-sanne said:

Turbo-Farmer said:

I had planned to pull the solution through the filter and into the syringe. After reading this, I'll probably pass on that approach. Having that option available does sound appealing, though. Still, I suspected it wouldn't work that smoothly.

The one-way aspect never crossed my mind.

Pushing on the plunger should let you use more force than pulling on it, I'd think. That's direct pressure rather than suction.

I gave that a shot too, haha. Filtering a second time isn't necessary for me, and it wouldn't work anyway.

Now I skip filtering altogether, since every method I've tried causes a big mess from spillage.

Working in biotech probably shaped how I see this. At a 0.2u pore size, we ran large 30” filters with a differential pressure of 30psi. Each run processed 30k litters.

Now that I’m the one at the helm, leaning on that filtration background just feels like second nature.

 

[Daisy333]

I ran into something similar, though in my case the filter wasn't to blame. It was my first attempt at reconstituting with both filtering and venting. I followed the Peptide Test youtube video for guidance, and I picked up both 1.5in needles and 0.5 needles.

So I put my bac water into the original vial containing the tirz, but when I went to pull the reconstituted solution back into the syringe before attaching the filter, nothing would come through the 1.5 inch needle. Eventually I gave up and swapped to the .5in needle, which did work. Maybe I was hitting the glass at the bottom, or maybe the needle was faulty. I plan to test with the old vial and syringes and water to check whether those needles function. But the main point is that having two different needle sizes isn't necessary, and I suspect they push that in those videos just to make you spend more.

Other newbie problems I had: I could never get the .5in needle off the syringe, and ended up using needle nose pliers, which obviously isn't sterile. Also, I figure I should buy smaller syringes. I have 10cc ones that I already had on hand, but they're far too big to measure accurately