The format for information on each facility addresses facility style, design intent, scientific reasoning, staffing, instrumentation, the science involved, and caseload. The labs profiled are the FBI Forensic Laboratory in Quantico, VA; the Forensic Science Center in Philadelphia, PA; the Regional Crime Laboratory in Los Angeles, CA; and the Forensic Biology Laboratory in New York, NY. The FBI Forensic Laboratory has the "Daisy Chain" facility style. The intent of this design is to allow each scientist to move in one direction into and out of each lab without back-tracking. The goal is to avoid cross-contamination. The Forensic Science Center in Philadelphia uses a "Horizontal" facility style. Developed from the Daisy Chain design, "Horizontal" flow facilities provide an even greater separation between preamplification and postamplification activities of DNA analysis in order to prevent cross-contamination. The Regional Crime Laboratory in Los Angeles is currently under construction. Its facility design provides for the separation of time and distance as a means of avoiding cross-contamination in DNA analysis. It will no longer be necessary to move from one space directly into the next. Staff and evidence will still move in one direction, but staff will be able to enter or exit the process at any point. The Forensic Biology Laboratory in New York City, which is currently under construction, uses a "verticle" facility style. The design allows for the vertical processing of evidence from floor to floor. "Dumb waiters" will move evidence from one floor to another. Scientists have access to each lab on every floor through Bio-Vestibules. This configuration gives staff the flexibility to access DNA analysis at multiple points while preventing cross-contamination. 4 figures