Our efforts are focused in 5 major areas:

• Develop new DNA assays that are more rapid and efficient than those currently used particularly with degraded specimens.
• Evaluate new genetic loci and develop technologies to aid forensic DNA typing.
• Develop DNA standard reference materials so that laboratories around the world may reliably compare their results.
• Conduct interlaboratory studies to improve understanding of factors impacting quality of results in DNA testing.
• Create standard information and training resources.

• Recent work has focused on human Y chromosome markers and improving capabilities for multiplex DNA analysis. Y chromosome short tandem repeat (STR) and single nucleotide polymorphism (SNP) markers have a number of applications in human identity testing including typing the perpetrator of sexual assault cases without differential extraction and tracing paternal lineages for missing persons investigations. http://www.cstl.nist.gov/biotech/strbase/pub_pres/Butler2003b.pdf
• Commercial kits have recently become available to aid analysis of Y-STR markers by the forensic DNA typing community. http://www.cstl.nist.gov/biotech/strbase/y_strs.htm
• These robust multiplex assays permit collection of information from many sites along the Y chromosome using only a very small amount of male DNA and even in the presence of high amounts of female DNA. http://www.cstl.nist.gov/biotech/strbase/multiplx.htm
• We have developed several new Y-STR multiplexes as well as evaluated various markers in the same reference set of DNA samples. http://www.cstl.nist.gov/biotech/strbase/NISTpop.htm
• A NIST Standard Reference Material ( SRM 2395 ) has been developed to help insure reliable measuring of Y chromosome DNA typing results around the world. http://www.cstl.nist.gov/biotech/strbase/srm2395.htm
• We are also developing resources and assays to aid working with challenging DNA samples, such as mixtures and degraded DNA (miniSTRs ). http://www.cstl.nist.gov/biotech/strbase/miniSTR.htm
• STRBase is a standard information resource: http://www.cstl.nist.gov/biotech/strbase .

• R. Schoske, P. M. Vallone, M. C. Kline, J. W. Redman, J. M. Butler, “High-throughput Y-STR typing of U.S. populations with 27 regions of the Y chromosome using two multiplex PCR assays,” Forensic Sci. Int.2004, 139, 107-121. http://www.cstl.nist.gov/biotech/strbase/pub_pres/Schoske2004.pdf
• P. M. Vallone, R. S. Just, M. D. Coble, J. M. Butler , T. J. Parsons, " A multiplex allele-specific primer extension assay for forensically informative SNPs distributed throughout the mitochondrial genome” Int. J. Legal Med, 2004, 118, 147-157. http://www.cstl.nist.gov/biotech/strbase/pub_pres/Vallone_IJLM2004.pdf
• M. C. Kline, D. L. Duewer, J. W. Redman, J. M. Butler “NIST mixed stain study 3: DNA quantitation accuracy and its influence on short tandem repeat multiplex signal intensity” Anal. Chem . 2003, 75,2463-2469. http://www.cstl.nist.gov/biotech/strbase/pub_pres/Kline2003.pdf
• J. M. Butler , Y. Shen, B. R. McCord, “The development of reduced size STR amplicons as tools for analysis of degraded DNA” J. Forensic Sci . 2003, 48, 1054-1064. http://www.cstl.nist.gov/biotech/strbase/pub_pres/Butler2003d.pdf