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Search Publications by: John Butler (Fed)

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Displaying 26 - 50 of 104

Forensic DNA Advisory Groups: DAB, SWGDAM, ENFSI, and BSAG

December 28, 2012
Author(s)
John M. Butler
A number of organizations exist around the world that work on a national or international level to aid quality assurance and to promote accurate forensic DNA testing. These organizations are made up primarily of working scientists who coordinate their

Developmental Validation of the PowerPlex(R) ESI 17 Pro System

December 27, 2012
Author(s)
Carolyn R. Steffen, Margaret C. Kline, John Butler, Robert S. McLaren, Jaynish Patel, Margaret Ewing, Douglas R. Storts, Fabrice Noel, Sophie Dognaux
The SE33 locus is one of the most polymorphic markers used in human identification. However, it also possesses multiple microvariants both within the repeat and in the flanking regions. Such flanking region mutations can generate discordant allele calls

The Latest and Greatest NIST PCR-based DNA Profiling Standard: Updates and Status of Candidate Standard Reference Material (SRM) 2391c

November 1, 2011
Author(s)
Margaret C. Kline, Carolyn R. Steffen, Jamie L. Almeida, Erica L. Romsos, Michael D. Coble, John M. Butler
Standard Reference Material 2391c (SRM 2391c) PCR-based DNA Profiling Standard is the third renewal of this SRM, originally released in 1995. SRM 2391c consists of 6 candidate components labeled A through F. Components A through D are supplied as genomic

STR Sequence Analysis for Characterizing Normal, Variant, and Null Alleles

August 1, 2011
Author(s)
Margaret C. Kline, Carolyn R. Steffen, John M. Butler, Amy Decker
DNA sequence variation is known to exist in and around the repeat region of short tandem repeat (STR) loci used in human identity testing. While the vast majority of STR alleles measured in forensic DNA laboratories worldwide type as "normal" alleles

Metrology Needs and NIST Resources for the Forensic DNA Community

June 1, 2011
Author(s)
Michael D. Coble, Margaret C. Kline, John M. Butler
With the advent of Forensic DNA profiling in the mid-1980s, this technology has had a positive impact on the criminal justice system, helping to convict the guilty and exonerate the innocent. The field has evolved from focusing on multi-locus markers

Scientific Issues with Analysis of Low Amounts of DNA

September 7, 2010
Author(s)
John Butler, Becky Steffen
Faced with limited evidence that yield low amounts of DNA, forensic analysts will continually have to confront the question of how far to push DNA testing techniques. Low copy number (LCN) analysis, also known as low template DNA (LT-DNA) testing, involves

Strategies for Concordance Testing

May 1, 2010
Author(s)
Carolyn R. Steffen, David L. Duewer, Margaret C. Kline, John M. Butler
Concordance evaluations are important to conduct to determine if there are any allelic dropout or “null alleles” present in a data set. These studies are based on the fact that there are a variety of commercial short tandem repeat (STR) multiplex kits

A New 26plex Autosomal STR Assay to Aid Human Identity Testing*(dagger)

September 1, 2009
Author(s)
Carolyn R. Steffen, John M. Butler, Peter Vallone
Multiplex polymerase chain reaction (PCR) has become the standard in forensic testing. Currently there are two commercial multiplex PCR amplification kits available that simultaneously amplify 16 short tandem repeat (STR) loci that include the 13 FBI

Demonstration of Rapid Multiplex PCR Amplification Involving 16 Genetic Loci

December 1, 2008
Author(s)
Peter Vallone, Carolyn R. Steffen, John M. Butler
Current forensic DNA typing is conducted in approximately eight to ten hours with steps including DNA extraction, quantitation, polymerase chain reaction (PCR) amplification of multiple short tandem repeat (STR) loci, capillary electrophoresis separation

Addressing Y-Chromosome Short Tandem Repeat(Y-STR) Allele Nomenclature

November 25, 2008
Author(s)
John M. Butler, Margaret C. Kline, Amy E. Decker
Currently 120 different Y-chromosome short tandem repeat (Y-STR) markers are used by various genetic genealogy testing laboratories. In some cases, different laboratories may designate the same Y-STR allele with two different nomenclatures making data

An Investigation of Discrimination Capacity and the Cause of Null Alleles in Linear Array Mitostrips Using Control Region Sequence Data.

October 16, 2008
Author(s)
Michael D. Coble, Margaret C. Kline, Janette W. Redman, Amy E. Decker, Peter Vallone, John Butler
Mitochondrial DNA (mtDNA) analysis of forensic evidentiary materials such as degraded bones and shed hairs can provide the forensic scientist with some genetic information especially when highly discriminatory systems, such as nuclear STRs, completely fail

Recent Developments in Y STR and Y SNP Analysis

October 16, 2008
Author(s)
John Butler
This article reviews new genetic markers on the Y chromosome and methods for analyzing these short tandem repeat (STR) and single nucleotide polymorphism (SNP) loci. Relative chromosomal locations for over 50 Y STRs are described along with their repeat

Characterization of 26 miniSTR loci for improved analysis of degraded DNA samples

January 25, 2008
Author(s)
Carolyn R. Steffen, Margaret C. Kline, Michael Coble, John M. Butler
An additional 20 novel mini-short tandem repeat (miniSTR) loci have been developed and characterized to aid in the analysis of degraded DNA samples. These new markers produce short PCR products in the target range of 50 150 base pairs (bp) by moving the

Concordance Study Between the AmpFlSTR((R)) MiniFiler(TM) PCR Amplification Kit and Conventional STR Typing Kits

July 25, 2007
Author(s)
Carolyn R. Steffen, Margaret C. Kline, Julio J. Mulero, Robert E. Lagace, Chien-Wei Chang, Lori K. Hennessy, John M. Butler
The AmpFlSTR MiniFiler PCR Amplification kit developed by Applied Biosystems enables size reduction on eight of the larger short tandem repeat (STR) loci amplified in the Identifiler kit, which will aid recovery of information from highly degraded DNA

Analysis of artificially degraded DNA using STRs and SNPs results of a collaborative European (EDNAP) exercise

December 1, 2006
Author(s)
L. A. Dixon, A. E. Dobbins, H. Pulker, John M. Butler, Peter M. Vallone, Michael D. Coble, W. Parson, B. Berger, P. Grubwieser, H. S. Mogensen, N. Morling, K. Nielsen, J. J. Sanchez, E. Petkovski, A. Carracedo, P. Sanchez-Diz, E. Ramos-Luis, M. Brion, J. A. Irwin, R. S. Just, O. Loreille, T. J. Parsons, D. Syndercombe-Court, H. Schmitter, B. Stradmann-Bellinghausen, K. Bender, P. Gill