U.S. flag

An official website of the United States government, Department of Justice.

New Methods for Next-Generation Sequencing Analysis of Damaged and Mixed DNA Samples

NCJ Number
Date Published
April 2020
2 pages

This article details a technique to make fragmented DNA more readable and a method to help pull individual profiles from mixed samples.


Investigators who use next generation DNA sequences to identify individuals may encounter degraded or mixed samples. Using funding from the National Institute of Justice (NIJ), Cassandra Calloway, a scientist at Children's Hospital Oakland Research Institute (California), has developed a technique to make fragmented DNA more discernible. She also designed, tested, and implemented an analytic tool that generates individual DNA profiles from a variety of mixture proportions. Both of these methods can be used for DNA profiling of samples too aged or damaged, such as those from the 9/11 attacks or the recent California wildfires, to produce any identifying information using standard forensic short tandem repeats. This article describes Calloway's research.

Date Published: April 1, 2020