CHHS Crime Scene Investigator (CSI) Certificate Practice Exam

In DNA analysis, STR stands for Short Tandem Repeats. These are sequences of DNA where a pattern of two or more nucleotides is repeated and the repetitions are directly adjacent to each other. STRs are crucial in forensic science because they are highly polymorphic, meaning that the number of repeat units can vary significantly among individuals. This variation allows for a high level of discrimination when comparing the DNA profiles of different individuals, making STR analysis a powerful tool in criminal investigations and paternity testing. STRs are specifically chosen for analysis in DNA profiling because they are relatively abundant in the human genome and can be amplified using polymerase chain reaction (PCR) with relative ease. This allows forensic scientists to generate profiles from very small amounts of DNA. The clarity and precision with which STRs can be analyzed are essential for identifying potential suspects in criminal cases or confirming biological relationships in civil matters.