If I receive a RM ATCC derivate with already three passages, does it mean that I could make no more than two passages in the lab? Moreover, from EURACHEM Guide 2023 is written that "Commercial derivatives of reference strains may only be used as working cultures" meaning that, if I buy ATCC derivates, it is suggested that I don't have to make stock cultures?. Thank you very much in advance, Davide Giovanardi
Hi Davide, According EP and USP it is recommended that “Seed lot culture maintenance techniques (seed-lot systems) are used so that the viable micro-organisms used for inoculation are not more than 5 passages removed from the original master seed-lot.” So that means it is possible to do 2 subcultures. But for example the Vitroids and Lenticule discs are intended for direct use as they are in ready to use concentration or can be directly diluted and show the typical characteristic properties. They are certified for the correct species, the certified cfu and the typical characteristic biochemical reaction and morphology. Strains from cell culture collections like ATCC use sometimes several passages/subcultures until they are fit and show typical characteristic properties in the tests or on the medium. Does it answer to your question ? All the best. Julien Pastor
If I receive a RM ATCC derivate with already three passages, does it mean that I could make no more than two passages in the lab? Moreover, from EURACHEM Guide 2023 is written that "Commercial derivatives of reference strains may only be used as working
cultures" meaning that, if I buy ATCC derivates, it is suggested that I don't have to make stock cultures?. Thank you very much in advance, Davide Giovanardi
Hi Davide, According EP and USP it is recommended that “Seed lot culture maintenance techniques (seed-lot systems) are used so that the viable micro-organisms used for inoculation
are not more than 5 passages removed from the original master seed-lot.”
So that means it is possible to do 2 subcultures. But for example the Vitroids and Lenticule discs are intended for direct use as they are in ready to use concentration or can be directly diluted and show the typical characteristic properties. They are certified for the correct species, the certified cfu and the typical characteristic biochemical reaction and morphology.
Strains from cell culture collections like ATCC use sometimes several passages/subcultures until they are fit and show typical characteristic properties in the tests or on the medium. Does it answer to your question ? All the best. Julien Pastor
Yes, thank you very much for your help