The chromosome-aberration cytogenetic bioassay (specifically lymphocyte dicentrics) is considered the gold standard in estimating dose. However, samples must be obtained after 24 hours of exposure, and results may not be available for 2 to 3 days, so time to emesis and lymphocyte counts remain the most useful tools in the initial assessment period. It is helpful to remember that if an individual has not vomited within 8 to 10 hours of exposure, it is unlikely he or she was exposed to a dose over 1 Gy. The Armed Forces Radiobiology Research Institute Biodosimetry Assessment Tool is a software package that can help providers assess exposure and guide therapy. The tool has a complimentary package for first responders called the First Responders Radiological Assessment Triage. These useful tools can facilitate optimization of a standardized framework for the response to nuclear or radiological incident.

The Department of Health and Human Services Radiation Emergency Management (REMM) webpage has interactive tools to assist with biodosimetry. These tools can be found at: https://remm.hhs.gov/ars_wbd.htm .