Does filtering work? Yep, lab tested....
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Ill also add that the concern of mycoplasma does not seem to be of high concern, since it has a very hard time surviving the lyophilization AND rehydration process, not even adding in the 0.9% alcohol we are all using in our BAC water.
@JtCjEfF Great article!
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You guys are much more informed than I am on this topic. Curious - if there were mycoplasma (or any other biological contamination) in these lyophilized powders that were destroyed during the lyophilization process, would the remains be considered endotoxins? Is there any filter that will get rid of those? Without damaging the peptides, of course?
@diannemccann Yes specifically these are designed for sterility and endotoxins and are the best way for a single vial peptide purchaser to deal with S&E if all they have is IPN on a peptide. Cytiva (PALL) 4908-N Acrodisc Syringe Filters Optimized for Scale Up, Posidyne membrane, sterile, 0.2 µm 25mm. .22 is the standard not .1
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@diannemccann Yes specifically these are designed for sterility and endotoxins and are the best way for a single vial peptide purchaser to deal with S&E if all they have is IPN on a peptide. Cytiva (PALL) 4908-N Acrodisc Syringe Filters Optimized for Scale Up, Posidyne membrane, sterile, 0.2 µm 25mm. .22 is the standard not .1
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I wanted to share this in the hopes that others might start sharing more testing info here on Peptide Critic....
I kept seeing people recommending to filter their peps and started doing some research. I found that the .2 micron filters, while good, aren't 100% for bacteria. Granted the bacteria they would miss are very rare and would not be commonly found in lyophilized peptides, but that less than 100% still bothered me.
Considering there has to be a practical and financial limit to the rabbit hole we go down for research peptide safety, and we all have to find our own comfort level with that, I started doing some more research.
I found sterile 0.1 micron filters for about $1 each and decided to go one step further and actually test them. We had a batch of Reta from JEEP that failed sterility at Janoshik. (also note that this is when we found out that Janoshik will allow someone to edit a report to change the company name, batch number, etc after the fact for a small fee. Def a red flag for doctoring "verified" tests at Janoshik).
I sent in two of those vials and two of the 0.1 Micron filters that I found. I had them reconstitute the two contaminated vials and test half of each vial unfiltered and half of each vial filtered. This confirmed for me that filtering (at least with the 0.1 micron filters) is viable and effective. Note I mistyped the MG size as 24mg instead of 34mg doh. Hope this is useful for somebody.
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Nice specific testing. Thanks!
I guess what we don't know with these results is wether the peptide itself survived the 0.1 micron filtration or not.
Btw, I tested the exact same batch, included endotoxins. These came good.
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@kRazy-pep Syringe filters cannot remove endotoxins. Endotoxins require special ultra resolution filter which may filter out entire peptide content leaving it useless for research. Only other way to remove endotoxins is high temp autoclaving. Not sure once endotoxins get into pep API whether they can be removed. The only way is to AVOID letting them in.
Syringe filters can only remove microbial contents and other larger impurities.
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@kRazy-pep No, the batch that failed endo was Tirz, this is Reta.
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@kRazy-pep Syringe filters cannot remove endotoxins. Endotoxins require special ultra resolution filter which may filter out entire peptide content leaving it useless for research. Only other way to remove endotoxins is high temp autoclaving. Not sure once endotoxins get into pep API whether they can be removed. The only way is to AVOID letting them in.
Syringe filters can only remove microbial contents and other larger impurities.
@pep_researcher Yes, I seem to be mixing up sterility and endo... I keep cracking my head on the sides of the rabbit hole as I tumble down.
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