Two whole genome amplification (WGA) methods--improved primer extension preamplification and multiple displacement amplification (MDA)--were tested with commercial kits.
The study found that WGA is of limited forensic utility unless the samples are of very high quality. The two WGA methods amplified DNA, but performed poorly on forensically relevant samples; the maximum amplicon size was reduced, and MDA often resulted in extraneous bands following polymerase chain reactions (PCR). Degraded DNA, which already has a susceptibility to amplification failure and allelic dropout, is likely to become worse after WGA. The random products that WGA, particularly the MDA procedure, generates from limited or no starting material can lead to the creation of multiple nonspecific PCR amplicons, further hampering further analyses. Commercially available kits designed for nonforensic material will need to be retooled if they are to have general applicability in forensic investigations. The study used control DNA; artificially degraded DNA; and DNA from fresh blood, aged blood, hair shafts, and aged bone. They underwent WGA followed by short tandem repeat and mitochondrial DNA analysis. The paper's section on materials and methods describes WGA optimization, the preparation of artificially degraded and forensically relevant DNAs, and assaying post-WGA products. 2 tables, 2 figures, and 21 references