Why are pus cells found in stool? A: Pus cells are commonly found in healthy stool, and they help to ease the passage of stool, according to About Health. However, these pus cells are not visible to the human eye. If pus, or mucus, is visible in the stool, this can indicate the presence of a disease or condition. Continue Reading.
DNA evidence is analyzed using the polymerase chain reaction (PCR) method, which allows for very small samples to be tested and identified. Once the sample is tested, it may be cross-referenced with DNA profiles already in a database or with genetic data provided by a suspect.
What happens to DNA evidence? Once DNA is collected, there is a protocol for how the evidence is handled and used in an investigation. The evidence will be provided to law enforcement who may send it to a crime lab. The lab will analyze the material and develop DNA profiles that are unique to a specific person. The lab works with law enforcement officials to compare these profiles to the DNA of potential suspects. If the perpetrator is unknown, they may compare the DNA profile against a large database run by the FBI called CODIS, the Combined DNA Index System.