Biomedical subjects
Publications and source records attributed to J D Ban.
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In the early 1990's, the importance of establishing a DNA Data Bank of convicted sex offender samples for comparison to unsolved cases became apparent to the Virginia Division of Forensic Science to help identify potential perpetrators. Ultimately, through the expansion of the data basing law to include all convicted offenders and juveniles convicted of a crime that would be considered a felony if tried as an adult, the Division has successfully used the DNA Data Bank to aid the law enforcement community in solving crimes where the victim was unable to identify the perpetrator. As the number of offender sample analyses has increased, in combination with the number of analyses of cases where a suspect could not be identified, the number of DNA Data Bank hits has also significantly increased. Initially, in 1997, when the Division converted its DNA Data Bank program from the restriction fragment length polymorphism technology to the short tandem repeat technology, one offender hit occurred on average for every 2,900 convicted offender samples that were entered into the Data Bank. However, by December 31, 2000, one DNA Data Bank hit occurred on average for every 700 samples entered into the Data Bank.
The success of the Virginia Division of Forensic Science's DNA program is based upon managing the DNA program from a central location, consistency in the methods and procedures used, cooperation and continual dedication of the laboratory staff, as well as overseeing of all technical issues by a single technical leader. To streamline the analysis of the evidence samples, the most probative items of evidence are examined first for biological materials. Once biological materials are identified, DNA analysis is performed and the resulting foreign short tandem repeat profile is entered into the Combined DNA Index Systems for routine searching of the profile against Virginia's and the nation's convicted offender DNA Data Banks. In addition, the foreign profile is also searched against other foreign profiles obtained from previously analyzed evidence samples, thereby helping the law enforcement agencies in Virginia solve crimes that would otherwise go unsolved.
Sonication procedures for the extraction of DNA from forensic-type semen specimens have been developed, which, when compared to currently utilized sperm DNA extraction techniques, are simple, rapid and result in comparable DNA yields. Sperm DNA extraction by sonication was performed on whole semen, seminal stains, buccal swabs and post-coital specimens. Ultrasound disruption of sperm cells and their ultimate release of cellular DNA has been conducted in the presence of sperm wash buffers followed by organic extraction or Chelex 100 with little or no compromise to DNA quality, quantity or amplifiability. Two advantages of sonication over currently used forensic techniques to extract sperm DNA include 1) sperm DNA extraction that occurs within five minutes of sonication compared with an hour or greater for water bath incubations in classic enzyme digestion DNA extractions and 2) one less preparatory step with the Chelex/sonication protocol and three less steps with the sonication/organic protocol compared with other procedures thus eliminating potential sample-to-sample cross-contamination. Sperm DNA extracted by optimum sonication procedures was used for forensic HLA DQ alpha typing and restriction fragment length polymorphisms analysis without any adverse effects on typing results.
Using HaeIII as the restriction endonuclease, restriction fragment length polymorphism analysis of dried blood samples from various animals was conducted. Single-locus probes D2S44, D10S28, D1S7, and D4S139, as well as monomorphic probe D7Z2, were used to examine for banding patterns. If bands were present, the samples were further examined for heterogeneity (whether single or multiple bands were observed) and polymorphism (whether variation in band location was shown between the animals studied within a species). Blood samples from animals, including primates, were obtained from Miami Metrozoo, Miami, Florida. Some of the animals were non-related individuals while others were related. Banding patterns were observed in colobus' for D2S44, D1S7, and D4S139; owl monkeys for D2S44; gorillas for D2S44 and D4S139; gibbons for D2S44 and D4S139; siamangs for D2S44, talapoins for DiS7; cranes for D1S7; and otters for D1S7. Based upon these, all of the animals for which a conclusion could be drawn appeared to be homozygous and monomorphic (exhibited only an invariant single band) for the loci examined except colobus' for D4S139, gorillas for D4S139, cranes for D1S7, and otters for D1S7.