Culture broth for biological indicators
Culture broths with reduced incubation time for biological indicators in strips or carriers
Biological indicators in strips or carriers are made up of bacterial spores inoculated on paper strips or other supports such as bars, threads, disks, of various materials including steel, cotton or glass fibre.
The carrier is usually enclosed in a paper sachet, which must be positioned inside the load and subjected to the sterilization cycle, during which the sterilizing agent comes into contact with the spores. For specific uses the carrier is presented naked, without a sachet.
At the end of sterilization, the carrier must be removed from the sachet and incubated for 7 days in Soybean Casein Digest Broth (TSB) and any cloudiness of the broth indicates bacterial growth and therefore sterilization failure.
Each manufacturer offers optimized culture broths equipped with a pH indicator which, by changing color with bacterial growth, allow shortening the incubation time. The manufacturer validates the reduced incubation time for its biological indicators, in relation to certain sterilization methods.