A biological sterilization indicator is disclosed that in some embodiments comprises a housing having a first enclosure and a second enclosure, an ampule containing a liquid growth medium, and an insert disposed at least partially in the first enclosure. A portion of the ampule may be disposed inside the first enclosure. The insert may have a platform including a top surface, an abutment surface, and a side surface, as well as a first void disposed in the platform and configured to allow passage of a first volume of the liquid growth medium into the second enclosure and a second void disposed through at least a portion of the side surface and configured to allow passage of a second volume of the liquid growth medium into the second enclosure. The second void of the insert may be an angled cut through the abutment surface and the side surface, which may be disposed entirely beneath the top surface. In some embodiments, stress concentrators and other features are included to reduce the force required to activate the biological sterilization indicator.
