I have an argument with colleagues and they tend to answer by experience, not by logical conclusions. How can a lyophilised powder, e.g. BSA, OVA, etc. be non-sterile? My colleagues argue that there are bacteria growing there (for example in the storage box in the fridge) but I really doubt that because all sources of life would need some basic materials, for example water, amino acids, sources of carbohydrated to survive and of course optimal conditions, e.g. temperature, moisture. All these definitely can't be found in a lyophilised powder in a storage box at 4-6oC. So, are powders sterile or not?
I agree with Akshamal. Add in the fact that there are bacteria growing in the fridge (test it!), and airborne contaminants if that bottle of powder has ever been opened outside a hood--and you have a potential for contamination. Viruses are metabolically inactive and growing, too, but they are also important sources of contamination. Yeast survive quite well in lyophilized form (most bread-baking and brewing yeast come "powdered") as well. If present, these yeast/bacteria/fungi (or spores thereof) still constitute contamination, even if they are not actively replicating.
The safest answer is to assume anything is contaminated until it is 1-autoclaved or 2-filter sterilized (in terms of liquids), even if made from a powder.
I agree with Akshamal. Add in the fact that there are bacteria growing in the fridge (test it!), and airborne contaminants if that bottle of powder has ever been opened outside a hood--and you have a potential for contamination. Viruses are metabolically inactive and growing, too, but they are also important sources of contamination. Yeast survive quite well in lyophilized form (most bread-baking and brewing yeast come "powdered") as well. If present, these yeast/bacteria/fungi (or spores thereof) still constitute contamination, even if they are not actively replicating.
The safest answer is to assume anything is contaminated until it is 1-autoclaved or 2-filter sterilized (in terms of liquids), even if made from a powder.
Total agreement Christina, As someone who produces sterile vaccine vials for the medical Bio Pharm Bio Vet arena
it is extreamly hard to produce anything as sterile by my professional TGA FDA DMF sterile product
As even the sterile so called autoclaved WFI and Filter sterilzed and gamma endotoxin free product is a very extensive task and have have showen even through all the above process I have seen contamination,
Some cases such as vacume sterile products such as NASA produces in new statalights are still recorded to have particular matter at miro levels present, so your freinds are right above to say that potential contamination is present
Regards
Dr Dean Kos
- Badges
- Science topic
- Similar topics
- Biological Science
- Microbiology