The use of transgenic crops expressing one or more crystal (Cry) proteins for insect management has grown dramatically since their introduction nearly 2 decades ago. However, many questions surrounding the environmental fate of these proteins still persist. One area of particular interest is the possible detection of Cry protein fragments by the antibodies used in ELISA kits. A model system approach is used to generate environmentally relevant fragments by simulating conditions and digestive enzymes that are known to exist in environments in which Cry proteins may be present. Seven different types of model systems were screened for their ability to generate fragments of the Cry1Ab protein; five of these model systems reliably generated Cry1Ab fragments. These fragments were analyzed in a subsequent study to determine whether the fragments were still detectable by ELISA and whether they retained any bioactivity.