The number of PCR cycles is often increased to improve the amplification yield from samples containing extremely low levels of DNA template. For example, by increasing the PCR cycle number from 28 to 34, STR typing results have been routinely demonstrated for samples containing less than 100 pg (Gill et al. 2000, Whitaker et al. 2001). However, application of LCN results should be approached with caution due to the possibilities of allele dropout, allele drop-in, and increased risks of collection-based and laboratory-based contamination.
Remarkably, DNA profiles may be obtained from fingerprint residues due to cells that are left on the objects that are touched (van Oorschot and Jones 1997, van Hoofstat et al. 1998, Abaz et al. 2002, Alessandrini et al. 2003). DNA technology may permit the handles of tools used in crimes, such as knives or guns, to be effectively evaluated and used to link a perpetrator to his crime. A nice review of the theory and application of trace DNA detection was published by Wickenheiser (2002).
The ability to obtain DNA profiles from small amounts of biological material has expanded the types of samples available for analysis. For example, crime scenes can contain insects that may be useful in linking a suspect to the crime in question. Several interesting studies have found that human DNA consumed by the insects may be extracted and successful identified. In particular, human crab louse feces have been reported as a source of human DNA (Replogle et al. 1994) as have mosquitoes (Kreike et al. 1999). As demonstrated by these examples, the capability of obtaining a useful DNA profile is often only limited by the ability of the forensic investigator to find and collect the appropriate evidence.
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This book discusses the futility of curing stammering by common means. It traces various attempts at curing stammering in the past and how wasteful these attempt were, until he discovered a simple program to cure it. The book presents the life of Benjamin Nathaniel Bogue and his struggles with the handicap. Bogue devotes a great deal of text to explain the handicap of stammering, its effects on the body and psychology of the sufferer, and its cure.