The allele drop-in phenomenon is usually not reproducible and can be detected through testing the sample multiple times. As noted in an early paper describing reliable genotyping of samples with very low DNA quantities, the probability of obtaining a particular extra allele (i.e., allele drop-in) does not exceed 5%, and thus the probability of obtaining this same extra allele in two independent PCR reactions is < 1% (Taberlet et al. 1996). Thus, the routine application of LCN involves at least two amplifications from the same DNA extract with a rule that an allele cannot be scored unless it is present at least twice in replicate samples (Taberlet et al. 1996, Whitaker et al. 2001, Gill 2001). The consensus or composite STR profile is then the one that is reported. This approach has been confirmed with consensus profiles from separate single cell PCR experiments matching the actual profile of the cell donor (Kloosterman and Kersbergen 2003).
It is essential that LCN be performed in a sterile environment to prevent contamination from laboratory personnel (Gill 2001, Rutty et al. 2003). DNA extractions and setting up PCR reactions should be performed in a dedicated laboratory similar to what is done in the 'ancient DNA' field (Capelli et al. 2003). Laboratory personnel should wear disposable lab coats, gloves, and face masks. In addition, benches and equipment should be frequently treated with bleach to destroy any extraneous DNA as previously described in Chapter 4. STR profile results should be compared against a staff elimination database as well as anyone who may have legitimately come in contact with the crime scene evidence prior to the DNA testing.
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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.