Abstract: A process for identifying the presence or absence of target objects inside or outside of cells is disclosed. The target objects are identified by highlighting them and collecting and analyzing image data. When target objects are present, the process can determine their size and/or shape and/or location. With this information, diseases, conditions, syndromes, or stimuli-induced effects may be diagnosed and/or courses of treatment monitored. The process may be used to determine the effect of stimuli on cells and can be used in the fields of medical diagnostics, drug efficacy screening, and drug toxicity screening. For example, after the appropriate test cells have been exposed to a chemical agent and allowed to undergo nuclear division, the micronuclei frequency determined indicates whether the chemical agent is clastogenic and/or aneugenic, which information can be used in a drug discovery program.