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Ensenberger M.G.,Promega Corporation | Thompson J.,Promega Corporation | Hill B.,U.S. National Institute of Standards and Technology | Homick K.,Buffalo Lab | And 13 more authors.
Forensic Science International: Genetics | Year: 2010

STR multiplexes remain the cornerstone of genotyping forensic samples. The PowerPlex® 16 HS System contains the core CODIS loci: D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, CSF1PO, FGA, TH01, TPOX, and vWA. Additional loci amplified in the multiplex reaction are the sex-determinant locus, amelogenin, and two pentanucleotide STR loci, Penta D and Penta E. The PowerPlex® 16 HS System is an updated version of the PowerPlex 16® System; while the primers and dyes remain unchanged, it introduces an enhanced buffer system that includes hot-start Taq DNA polymerase and ensures robust performance. Due to the modification of the reaction mix, a multi-laboratory developmental validation study was completed to document performance capabilities and limitations for the revised assay. Data within this validation was generated by eight laboratories and served as the basis for the following conclusions: genotyping of single-source samples was consistent across a large range of template DNA concentrations with most laboratories obtaining complete profiles at 62.5 pg. Mixture analyses showed that over 90% of minor alleles were detected at 1:9 ratios. Optimum amplification cycle number was ultimately dependent on the sensitivity of the detection instrument and could be adjusted to accommodate a range of DNA template concentrations. Reaction conditions including volume and annealing temperature as well as the concentrations of primers, Taq DNA polymerase, and magnesium were shown to be optimal and able to withstand moderate variations without affecting multiplexed STR amplification. Finally, data from non-probative samples and concordance studies showed consistent results when comparing the PowerPlex® 16 HS System with the PowerPlex® 16 System as well as other commercially available systems. © 2009 Elsevier Ireland Ltd. All rights reserved.


Tiscione N.B.,Palm Beach County Sheriffs Office | Yeatman D.T.,Palm Beach County Sheriffs Office | Shan X.,Palm Beach County Sheriffs Office | Kahl J.H.,851 NW 10th Ave
Journal of Analytical Toxicology | Year: 2013

Volatiles are frequently abused as inhalants. The methods used for identification are generally nonspecific if analyzed concurrently with ethanol or require an additional analytical procedure that employs mass spectrometry. A previously published technique utilizing a capillary flow technology splitter to simultaneously quantitate and confirm ethyl alcohol by flame ionization and mass spectrometric detection after headspace sampling and gas chromatographic separation was evaluated for the detection of inhalants. Methanol, isopropanol, acetone, acetaldehyde, toluene, methyl ethyl ketone, isoamyl alcohol, isobutyl alcohol, n-butyl alcohol, 1,1-difluoroethane, 1,1,1-trifluoroethane, 1,1,1,2-tetrafluoroethane (Norflurane, HFC- 134a), chloroethane, trichlorofluoromethane (Freon®-11), dichlorodifluoromethane (Freon®-12), dichlorofluoromethane (Freon®-21), chlorodifluoromethane (Freon®-22) and 1,2-dichlorotetrafluoroethane (Freon®-114) were validated for qualitative identification by this method. The validation for qualitative identification included evaluation of matrix effects, sensitivity, carryover, specificity, repeatability and ruggedness/robustness. © The Author (2013). Published by Oxford University Press. All rights reserved.


Tiscione N.B.,Palm Beach County Sheriffs Office | Vacha R.E.,Orlando Regional Operations Center | Alford I.,Palm Beach County Sheriffs Office | Yeatman D.T.,Palm Beach County Sheriffs Office | Shan X.,Palm Beach County Sheriffs Office
Journal of Analytical Toxicology | Year: 2015

The effect of long-term room temperature storage on the stability of ethanol in whole blood specimens was investigated. One hundred and seventeen preservedwhole blood case samples (110 of 117with two tubes of blood in each case) were used for this study. One tube from each case was initially tested for blood alcohol concentration (BAC) for criminal driving under the influence proceedings. Cases positive for ethanol ranged in BAC from 0.023 to 0.281 g/dL. The second tube, if present, remained sealed. All blood samples were then stored at room temperature. After 5.4-10.3 years, the opened tubes were reanalyzed for BAC by the same laboratory that performed the initial testing using the same method and same instrumentation. After the same storage period, the unopened tubes were sent to a different laboratory, using a different method and different instrumentation, and reanalyzed for BAC after a total of 5.6-10.5 years of room temperature storage. Seven samples initially negative for alcohol remained negative. All samples initially positive for ethanol demonstrated a decrease in BAC over time with a statistically significant difference in loss observed based on blood sample volume and whether or not the tube had been previously opened. The decrease in BAC ranged from 0.005 to 0.234 g/dL. Tubes that were not previously opened and were more than half full demonstrated better BAC stability with 89% of these tubes demonstrating a loss of BAC between 0.01 and 0.05 g/dL. © The Author 2015.


Tiscione N.B.,Palm Beach County Sheriffs Office | Shan X.,Palm Beach County Sheriffs Office | Yeatman D.T.,Palm Beach County Sheriffs Office
Journal of Analytical Toxicology | Year: 2014

An evaluation of an internal laboratory decision to implement a protocol for limiting drug testing based on ethanol concentration in laboratory analysis for driving under the influence (DUI) cases is presented. The described case management strategy is supported by known impairment of ethanol at relatively high concentrations, difficulty assigning a level of contributing impairment from drugs in the presence of high ethanol levels and the likelihood that the drug results may be suppressed at trial. Although the results of this study reinforce the assertion that such protocols lead to the under reporting of drugs in DUI cases, for the majority of cases, 95% in this study, the drug analysis results were not significant and did not warrant the time and resources needed for the additional blood drug testing. Furthermore, the study demonstrated that a high drug positivity rate does not necessarily mean that those drug results are legally or pharmacologically meaningful. Additional research should be conductedwith quantitative drug results and casework impact of blood drug screen protocols as previous studies only report drug positivity rates and not whether the drug results would be meaningful to the case. © The Author 2014. Published by Oxford University Press.


Tiscione N.B.,Palm Beach County Sheriffs Office | Alford I.,Palm Beach County Sheriffs Office | Yeatman D.T.,Palm Beach County Sheriffs Office | Shan X.,Palm Beach County Sheriffs Office
Journal of Analytical Toxicology | Year: 2011

Ethanol is the most frequently identified compound in forensic toxicology. Although confirmation involving mass spectrometry is desirable, relatively few methods have been published to date. A novel technique utilizing a Dean's Switch to simultaneously quantitate and confirm ethyl alcohol by flame-ionization (FID) and mass spectrometric (MS) detection after headspace sampling and gas chromatographic separation is presented. Using 100 μL of sample, the limits of detection and quantitation were 0.005 and 0.010 g/dL, respectively. The zero-order linear range (r 2 > 0.990) was determined to span the concentrations of 0.010 to 1.000 g/dL. The coefficient of variation of replicate analyses was less than 3.1%. Quantitative accuracy was within ±8%, ±6%, ±3%, and ±1.5% at concentrations of 0.010, 0.025, 0.080, and 0.300 g/dL, respectively. In addition, 1,1-difluoroethane was validated for qualitative identification by this method. The validated FID-MS method provides a procedure for the quantitation of ethyl alcohol in blood by FID with simultaneous confirmation by MS and can also be utilized as an identification method for inhalants such as 1,1-difluoroethane.

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