Within the Rapid Stain Identification (RSID) Series, developed by Independent Forensics, there are four different types of field kits: blood, urine, semen, and saliva. These kits bring together several advantages: (1) they are sensitive enough to detect as little as one micro liter of blood, saliva, semen, or urine; (2) by design, if the test produces a positive result, there is enough biological material present for successful DNA STR analysis; and (3) they are specific only to human body fluids meaning they will not cross-react with other animal fluids. The kits are very simple to use. They are designed so that they may be used with both liquid and dried samples, as well as stains on absorptive or non-absorptive materials. Evidence technicians, who spend the majority of their time working in the field, are always looking for faster, easier ways to identify the best evidence, collect it, and get it back to the laboratory for analysis. Presumptive tests that help identify the presence of specific body fluids are essential tools to evidence technicians processing the scenes of sexual assaults.