Dear Sirs

USP recommends use of 10 to 30ml culture media for each strip to submerge the biological indicator (Bacillus atrophaeus) completely.

Do You think if is possible to put ten (10) paper in a tube with 15 ml of the media culture?

Thank You very much for Your attention,

Valdir

Dear Valdir,

to allow any surviving spores to grow, certain optimal incubation conditions have to be met. These include temperature but also type and amount of broth. In addition if you "bundle" spore strips into one broth container, you lose the information on how many of the spore strips showed survivors as well as from which spot in your load/chamber the spore strip(s) come. These information can be vital to judge a process and identify weaknesses like sterilant penetration.

Furthermore the method suggested by you would be outside of USP procedures and might lead to non-compliance with e.g. audits and inspections.

Kind regards
Dr. Brian Kirk / Klaus Hahnen (3M Laboratories, Europe)