Serology is concerned with the examination and identification of bodily fluids. Evidence items found at a crime scene might be submitted to determine if they exhibit biological stains such as blood, semen or saliva that may be identified to a specific individual. Rape kits taken from a victim at a hospital are an example of evidence that would be analyzed in this section.
DNA analysis is used to compare evidence samples such as the serological stains above to known standards from a victim or suspect. This section utilizes a DNA database system known as CODIS (Combined DNA Index System).
This system links labs nationwide in order to compare DNA profiles (unique genetic markers). It can link suspects and victims to each other or to specific crime scenes. It can also be used to link multiple cases such as serial rapists.