NCJ Number
209745
Journal
Journal of Forensic Sciences Volume: 50 Issue: 3 Dated: May 2005 Pages: 571-578
Date Published
May 2005
Length
8 pages
Annotation
This article reports findings from the 2004 National Institute of Standards and Technology (NIST) interlaboratory study that assessed the accuracy of DNA quantitation in forensic DNA laboratories.
Abstract
To gain the optimal results for DNA short tandem repeat (STR) typing, the DNA concentration of the sample should be accurately determined prior to the polymerase chain reaction (PCR) amplification step. The study by NIST was designed to (1) examine concentration effects and determine performance at the lower DNA concentration levels frequently used in casework; (2) to measure consistency with various methodologies across laboratories; (3) to examine single versus multiple source samples; and (4) to assess DNA stability over time and through shipping using two types of storage tubes. Materials consisted of 8 extracted DNA samples that were mailed to 84 laboratories; 80 laboratories returned 1 or more sets of results for a total of 287 independent datasets. Results were obtained using 19 different DNA quantitation methodologies: 65 percent were obtained using traditional slot blot hybridization methods and 21 percent were obtained using newly available real-time PCR techniques. The result distributions were similar for all quantitative methods. Tables, figures, references