Syringe gauge selection and sterile filtering loops for vial reconstitution

Not certain whether the mixup happened by design, but it looks like the filter pore dimensions might be mixed up. Perhaps 22 micron ones were acquired, though the standard dimension that gets used most often, which is what I typically purchase, comes in at 0.22 micrometers.

Another thread covers worries over how it dissolves and if it clumps even once diluted.

Ugh this forces me into signing up there now

Being new here I'm working to figure out these steps. It sounds like the method starts by injecting one milliliter into the first vial for mixing. That gets filtered over to a second vial. Then another milliliter plus a bit extra goes back into the first one for rinsing, gets drawn out, filtered, and added to the second. The part I'm stuck on is the timing for swapping syringes and needles throughout. Would the same ones handle the water additions to both vials or get replaced? Is the needle left connected to the filtered vial so the rinse can be attached right away? Overall the steps make sense to me except for those equipment changes. Everything else matches what you said on supply costs, but the filters are where I differ and wonder about the lower amount.

Although the question wasn't aimed at me I still wanted to mention filters. I came across a firm that handles full lines for preserving biological samples in the cold along with setups for growing cells and assorted everyday lab items. Their main offerings include sieves for cells tubes meant for freezing cardboard containers suited to low temperatures and ends for pipettes plus similar things.

Have you picked up any from that set of 140? Your handle never showed in the mentions here or over there. Maybe posted under something else instead?

I begin with a syringe holding three milliliters of preserved water and add it to the dried powder vial. After the powder dissolves through slow rolling motions on a flat surface, the mixture gets pulled back into the syringe. I swap the connection to include a filtering attachment, then fit a new needle on the end. Next I insert the needle into a pen cartridge or clean storage container and ease the solution across the filter membrane. Pen users also insert a separate cheap needle through the top to equalize pressure and keep the internal plunger from sliding out during the transfer. Once the liquid has crossed over, the needle is withdrawn slightly into the headspace so any spring-back pulls only air instead of product. Adding a small air volume and forcing it through afterward helps pull extra liquid from the filter pores. I skip extra water rinses or pre-wetting steps that some mention.

Different name, I have bought "some".

Appreciate the tip since this beats arriving late at the peak. Grateful for those extra specifics. I have one query on the steps involved. After mixing the solution do you keep the needle and syringe inside the container while swirling everything?

Tried both approaches myself. Pulling the needle free and just turning the container around feels smoother overall. Thought maybe some stuff would drip out but nothing ever did.

I left out the period without meaning to. Everything I mentioned applies to the point twenty two micron variety of filters.

My bad everyone, I missed putting the decimal in when describing those filters earlier. I intended to say .22 micron or .22um.

As someone just starting out I'm curious about the advantages of using filters this idea is unfamiliar to me could someone explain the reasons behind doing it and point me to resources for further reading

Growing mushrooms taught me that UV sterilizers never get the job done. I picked up a pressure cooker instead and ran it for ninety minutes at fifteen psi even though half an hour is sometimes mentioned.

These filters use pores measuring 0.22 micrometers to trap bacteria that typically range from 0.5 to one micrometer so any contamination stays behind while viruses and endotoxins pass through unaffected. Sizes vary as well with four thirteen or twenty five millimeter widths being typical. Wider versions process larger amounts before clogging but leave more liquid trapped inside the material. When I mixed peptides into three milliliters of bac water the thirteen millimeter size worked out best since roughly a tenth of a milliliter or ten units remained stuck though an air push or extra water run recovered most of it.

Appreciate you explaining everything in detail like that. Also grateful for the provided link. This will send me exploring further into the topic. Having experience with sterile setups from my other interest, I'm now curious whether others typically handle this task under clean conditions. Seems like my flow hood setup is about to see increased activity.

Jealous! Owning a clean air workstation would be awesome. Although employed at a scientific workplace, borrowing their device for side experiments probably wouldn't go over well, heh. My home alternative is an enclosed still air setup, offering less cleanliness than the hood yet superior to exposed surfaces.

Wondering about a budget friendly reputable alternative to the recommended spot for all of it. Saw some groups of ten filters available.

☝️

This has me concerned. Since certain outlets market 18 gauge blunt needles for filtration tasks, it looks like the possibility could be real.

Twenty five gauge handles my filtration needs. A narrower size would suit the mixing stage and straining better except the strands turn far too unstable to manipulate properly.

That really stressed out my lazy side with all the effort involved... Is every container handled exactly like this?

1000000% this.

Sure thing, nothing but total sterility works for my RS. It starts off feeling involved, but before long it just becomes routine.

Y'all have talked me into it. I have 23g.

Not super strict on the rules, yet it generally seems logical. When needed, various options can handle reconstitution. Typically I go with a 25 gauge 3ml syringe, though I've tried 31 gauge 1ml insulin ones in the past.

Curious how many of us share another hobby that also calls for sterile conditions. A Venn diagram of the overlap would be interesting to see.

Right. The contaminants would remain inside the vial and the needle.

Know this thread is older, but wanted to say thanks anyway. Completed my first reconstitution and filtering last night and the guide made a big difference.

Thanks for the note. One spot in the description wasn't quite right. It should say to disconnect the syringe from the filter when drawing air for the purge step after filtering, not from the needle. Pulling air back through the filter itself wouldn't be the way to go.

Went ahead and did it. Allowed a bit of extra volume, ran it through the filter, and everything is performing as expected with no noticeable change from the single bottle I used before.

Figured that part out already. It just made sense not to do it the other way. Appreciate the extra detail though.

Really glad it went well. Nice to hear you're having a positive experience with it.