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Ballantyne K.N.,Office of the Chief Forensic Scientist | Ballantyne K.N.,La Trobe University | Salemi R.,Biology Division | Guarino F.,Biology Division | And 4 more authors.
Australian Journal of Forensic Sciences | Year: 2015

Recent environmental monitoring studies have highlighted a need to confirm cleaning procedures are performing to suitable levels for highly sensitive STR kits such as PowerPlex 21. To ensure that DNA contamination minimisation procedures are adequate, we have investigated the efficacy of sodium hypochlorite and a commercial, non-corrosive alternative, Virkon, at a range of concentrations for their DNA decontamination ability. Cleaning solutions were trialled across a range of body fluids and surface types, to cover the variety of potential contamination circumstances encountered within typical forensic laboratories. Given all factors tested, it was concluded that a 1% solution of sodium hypochlorite, sprayed on the surface and left for 5 min before drying and wiping with 70% ethanol, was able to remove DNA, saliva, blood, semen and skin cells from both smooth and pitted surfaces. However, safety testing revealed that the combination of hypochlorite and ethanol produced levels of gaseous chlorine at or above the recommended exposure limits. Subsequently, a cleaning protocol of 1% hypochlorite followed by distilled water was tested for efficacy, and subsequently introduced throughout the laboratory. © 2015 Australian Academy of Forensic Sciences.

Verdon T.J.,Biology Division | Verdon T.J.,La Trobe University | Ballantyne K.N.,Biology Division | Mitchell R.J.,La Trobe University | van Oorschot R.A.H.,Biology Division
Forensic Science International: Genetics Supplement Series | Year: 2011

The Pinpoint DNA Isolation System (Zymo Research) uses a dissolved polymer compound to remove and extract DNA from slide mounted pathology specimens. This polymer is applied to a non-porous substrate on which biological material is deposited, allowed to dry, and the polymer, containing cells and DNA, is peeled off. The polymer dissolves into solution during extraction, theoretically releasing more DNA into the extract than standard cotton swabs; a notion supported by initial data. We performed preliminary experiments to test its effectiveness in comparison to wet/dry swabbing methodology for forensic samples, including replicates each of 10. μL of saliva on glass slides and a pitted, non-porous surface. Results from the glass substrates showed that the initial application method of spreading with pipette tips generated significantly less DNA than the swabbing method. The mode of polymer application is being investigated further with the aim of improving DNA collection. Sampling from a pitted surface with Pinpoint exhibited significantly less variability than swabbing, but the mean quantity of DNA obtained from both collection methods was comparable. The Pinpoint system, combined with an optimised application method, may be another effective way to sample DNA in forensic casework. It has the potential to collect higher quantities of DNA than traditional methods which may be especially advantageous in casework involving trace DNA. © 2011 Elsevier Ireland Ltd.

Verdon T.J.,Biology Division | Verdon T.J.,La Trobe University | Mitchell R.J.,La Trobe University | van Oorschot R.A.H.,Biology Division
Forensic Science International: Genetics Supplement Series | Year: 2011

The efficiency of extracting DNA directly from substrates varies according to a range of factors including the type of substrate and the extraction technique. Two routinely used DNA extraction methodologies (automated DNA IQ and manual Chelex) were texts on their efficiency to extract DNA from a range of blood volumes (0.1-30. μL) on plastic and cotton. The efficiency of extracting DNA from plastic appeared to be lower than from cotton for both methods, but was only statistically significant for Chelex extractions. Pairwise comparisons of blood volumes extracted using DNA IQ showed statistically significant differences. Comparisons of Chelex extractions of different blood volumes also showed significant differences for cotton, but not for plastic. The threshold effect of DNA IQ was only demonstrated at blood volumes above 15. μL. This preliminary research highlights discrepancies between extraction methods and demonstrates that laboratories should be aware of the limitations of their analysis techniques, as knowledge of extraction efficiencies may assist in optimisation of methodologies and procedures. Extraction efficiency analysis will also allow for more accurate assessment of the influence of used methodologies in studies relating to determination of DNA transfer rates, and, should these transfer studies be put into practice, in casework. © 2011 Elsevier Ireland Ltd.

Ballantyne K.N.,Biology Division | Ballantyne K.N.,La Trobe University | Van Oorschot R.A.H.,Biology Division | Mitchell R.J.,La Trobe University
Forensic Science International: Genetics | Year: 2011

Inadequate sample quantities and qualities can commonly result in poor DNA amplification success rates for forensic case samples. In some instances, modifying the PCR protocol or components may assist profiling by overcoming inhibition, or reducing the threshold required for successful amplification and detection. Incorporation of locked nucleic acids (LNAs) into PCR primers has previously been shown to increase amplification success for a range of non-forensic sample types and applications. To investigate their use in a forensic context, the PCR primers for four commonly used STR loci have been redesigned to include LNA bases. The modified LNA primers provided significantly increased amplification success when compared to standard DNA primers, with both high-quality buccal samples and simulated forensic casework samples. Peak heights increased by as much as 5.75× for the singleplex amplifications. When incorporated into multiplexes, the LNA primers continued to outperform standard DNA primers, with increased ease of optimisation, and increased amplification success. The use of LNAs in PCR primers can greatly assist the profiling of a range of samples, and increase success rates from challenging forensic samples. © 2010 Elsevier Ireland Ltd. All rights reserved.

Bikshapathi R.,Indian Institute of Chemical Technology | Prathima P.S.,Indian Institute of Chemical Technology | Yashwanth B.,Biology Division | Pamanji R.,Biology Division | And 5 more authors.
Monatshefte fur Chemie | Year: 2016

Abstract: A series of C(3)-trifluoromethylated compounds derived from N-substituted isatins were synthesized. The biological activity of all 3-hydroxy-3-(trifluoromethyl)indolin-2-one derivatives have been evaluated for in vitro cytotoxic activity and antibacterial activity. The active compounds were screened against nuclear xenobiotic receptor CAR (PDB ID: 1XLS), PIM1 kinase (PDB ID: 2O65), and CDK2 kinase (PDB ID: 3QHR) by using in silico molecular docking studies to obtain lead molecules. In addition to its potential anticancer activity, 5-bromo-3-ethynyl-3-hydroxy-1-(prop-2-yn-1-yl)indolin-2-one also showed specific antibacterial activity against S. aureus.Graphical abstract: [Figure not available: see fulltext.] © 2016 Springer-Verlag Wien

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