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DNA & biological evidence


DNA is a complex molecule that contains the instructions for building and maintaining the bodies of humans and other organisms. With the exception of red blood cells, every cell in your body has DNA. And with the exception of identical twins, everyone’s DNA is different. If someone leaves blood, semen or other biological material at a crime scene, scientists can use it as DNA evidence and create a DNA profile, or genetic fingerprint of that person. That profile can be used to search a DNA database for a possible suspect, to associate a suspect with evidence left at a crime scene, or to link two crimes that may have been committed by the same person. DNA profiles, and some of the complications in using them, are described in this article about enhanced DNA fingerprints.


NIST has played a key role in the historical development of forensic DNA analysis. Today, our forensic DNA program has three major components.

News and Updates

Projects and Programs

Digital PCR

Digital PCR (dPCR) is a method used to quantify nucleic acids (DNA, RNA, cDNA). At NIST we are using microfluidic and emulsion-based dPCR platforms for


The Biological Evidence Preservation Handbook: Best Practices for Evidence Handlers

Susan M. Ballou, Margaret C. Kline, Mark D. Stolorow, Melissa K. Taylor, Shannan R. Williams, Phylis S. Bamberger, Burney Yvette, Larry Brown, Cynthia E. Jones, Ralph Keaton, William Kiley, Karen Thiessen, Gerry LaPorte, Joseph Latta, Linda E. Ledray, Randy Nagy, Linda Schwind, Stephanie Stoiloff, Brian Ostrom
The report of the Technical Working Group on Biological Evidence Preservation offers guidance for individuals involved in the collection, examination, tracking

The Future of Forensic DNA Analysis

John M. Butler
The author’s thoughts and opinions on where the field of forensic DNA testing is headed for the next decade are provided in the context of where the field has