Okay, quite a bit to unpack right here, however please don’t take this the flawed manner. I’ve labored for six+ years in scientific laboratories, together with 3 in a BSL-2 lab (the place we work with infections bloodborne pathogens).
Sterile, aseptic work can completely be achieved at house, however correct procedures have to be adopted, and those that try it must also perceive why they’re achieved.
Boiling the vial is an effective approach to remove most microbes and inactivate spores, however provided that achieved for 10 minutes or extra with the whole vessel (cap and glass) submerged. I assume that’s what you do. Nonetheless, rinsing it afterwards with isopropanol is harmful, particularly in case you are rinsing the inside, as you’ll be risking the reintroduction of microbes and/or contaminants to the container. This will likely not make sense, as isopropanol is often used as a disinfectant/sanitizer. Nonetheless, spores can simply survive in isopropanol within the dormant state, and most commercially offered isopropanol is just not sterile. Spores can simply survive months to even a 12 months in ethanol, which is extra antimicrobial than isopropanol. I perceive the will for extra sterility, however this step will be skipped as it will compromise sterility. In addition to, a ten minute boil already ensures sterility past what isopropanol can supply.
This suggests that you’re opening the sterilized glass vial and allotting non-sterile resolution into your sterilized container. This defeats the aim of your prior sterilization. Like I stated earlier than, process issues, and order of operations have to be adopted until you need your legs to necrose from spore contamination of your resolution.
Until the options/reagents that you simply purchase particularly state on the container, certificates of research, or security information sheet sheet that it’s sterile, it’s not sterile. The DMSO that you’ve is just not sterile, and neither is the rapamycin powder. Sure, rapamycin is antifungal, however that doesn’t imply it’s sterile, particularly in its desiccated powder type.
The right approach to do it will be to combine your resolution beforehand (DMSO plus rapamycin), then use a sterile syringe to attract up the answer and cross it via a 0.22 micron filter into the sterile container.
Additionally, because you made no point out of utilizing a nonetheless air field, I’ll assume that you’re not utilizing one and easily doing it within the open air of your own home. That is actually the half that issues me essentially the most.
Clear to the attention doesn’t imply that there are not any particles within the resolution, as the attention can not understand microscopic particles. Your best danger of contamination is probably going from this step, as most city properties can comprise a median of 14,500 ultrafine particles per cubic centimeter, and that’s not even mentioning the particulates which can be smaller than that! That is why, in scientific labs, we use laminar-flow hoods with the very best grade HEPA filters, amongst different controls.
While you open your sterilized container, you might be exposing it to those particles and welcoming them to land inside it. Such particles can carry an ungodly quantity of contaminants, starting from mites to spores to plastics and who is aware of what else in these instances! Thankfully, you’ll be able to simply make a nonetheless air field at house for fairly low-cost with only a plastic field and a few instruments. Mushroom growers generally make them to be able to guarantee their harvests stay uncontaminated by different fungi/spores, however the precept used is identical as within the scientific lab.
Here’s a information on learn how to make one for round $20. Granted, there are even higher designs on the market, however it is a good funds methodology.
Personally, I might use 10% bleach as an alternative of 70% isopropanol to deal with the field for causes I said above, nevertheless it’s not completely essential. I might simply add that after sanitizing the surfaces, you need to place all of your working supplies into the nonetheless air field, cowl the holes, and wait at the least 45-60 minutes to make sure that all micron-and-smaller particles or aerosols settle earlier than starting work. Additionally, put on gloves and canopy your arms with non-linting materials akin to a water-proof windblocker or seran wrap, as uncovered pores and skin can flake of various high-quality particles (an excellent portion of family mud is lifeless pores and skin floating round). Enter the nonetheless air slowly, and work steadily. Fast motion can attract air from the surface. Make sure to maintain all bottles and containers coated, particularly your sterile container, till you have to add reagents, and re-cover afterwards.
This half is okay, as long as you observe the procedures I described above. When you make your resolution within the nonetheless air field, use your sterile syringes to attract it up, re-cap with one-handed method, and proceed as traditional.
In case you have been utilizing your older protocol, I might have really helpful utilizing a multi-dose vial with a crimped septa prime to retailer your resolution, however I actually assume your newer protocol is healthier as you decrease freeze/thaw and the variety of manipulations (and thus potential for contamination). I don’t know what sort of syringes you might be utilizing, however I might strongly suggest low lifeless quantity syringes to scale back the quantity that’s wasted per shot, particularly contemplating the price of rapamycin. Undecided how effectively these would deal with the freezer, although.
General, I believe it’s fortunate that you simply haven’t gotten a severe an infection but. Granted, it’s akin to driving and not using a seatbelt. The danger of such a factor taking place is low, however the penalties when it does happen will be fairly severe, and will even value you your life. Compounding your individual sterile medication isn’t any joke!
BTW, there are methods to attain autoclave-level sterilization at house. This paper demonstrates that an On the spot Pot is able to inactivating Geobacillus stearothermophilus spores, which in scientific labs is taken into account the gold commonplace. A stovetop stress cooker or canner may attain 15 PSI, which may create autoclave temperatures.
I’m personally curious as as to whether one can autoclave a rapamycin resolution in a sterile container like a multi-dose vial. That may be my most well-liked methodology, however I’m unsure if rapamycin is heat-stable sufficient for that. My hunch is that it’s not, being a fairly massive molecule, so I believe your methodology is probably going the way in which to go.
EDIT: I forgot to say that you need to ideally depyrogenate all of the glassware that may contact your resolution by baking them in an oven at 450 F for two hours, minimal. Additionally, 0.22 micron filters won’t defend you from sure mycoplasma strains which can be sufficiently small to cross via even that pore dimension, however infections from these are exceedingly uncommon and filters are arduous to supply/costly, to not point out much more of a PITA to push fluid via. 0.22 is sweet sufficient IMO.
