A biological sterilization indicator is disclosed that in some embodimentscomprises ahousing having a first enclosure and a second enclosure, an ampule containinga liquid growthmedium, and an insert disposed at least partially in the first enclosure. Aportion of the ampulemay be disposed inside the first enclosure. The insert may have a platformincluding a topsurface, an abutment surface, and a side surface, as well as a first voiddisposed in the platformand configured to allow passage of a first volume of the liquid growth mediuminto the secondenclosure and a second void disposed through at least a portion of the sidesurface andconfigured to allow passage of a second volume of the liquid growth mediuminto the secondenclosure. The second void of the insert may be an angled cut through theabutment surface andthe side surface, which may be disposed entirely beneath the top surface. Insome embodiments,stress concentrators and other features are included to reduce the forcerequired to activate thebiological sterilization indicator.
