Paternity and Parentage Testing

In brief, the limitation of the method includes a smaller number of alleles and less heterozygosity per locus; the possibility of contamination from stray DNA is increased because of the amplification process. The amplification process also may lead to the formation of "stutter bands", artifacts or preferential amplification, leading to imprecise interpretation of the result. For some automated uses, the equipment is relatively expensive if high-throughput analysis of fluorescent labeled multiplex systems are undertaken.

With the recent automation and miniaturization of DNA typing methods, the analysis of polymorphism began to revisit the single nucleotide polymorphism analysis (SNPs), another form of loci polymorphism. They were first described about in the 1980s, but only recently are being studied for paternity analysis. They are abundant in the genome and perceived as being more stable than STRs due to lower mutation rates.

In parallel to that, two other techniques are being utilized with specific objectives. They include mitochondrial DNA and Y chromosome DNA analysis. Mitochondrial DNA (mtDNA) is a double-stranded DNA found in the mitochondria, transmitted only by the egg. Therefore, mtDNA is particularly useful in the study of individuals related through the female line. Alternatively, the Y chromosome is transmitted from the father only, so DNA on the Y chromosome can be used to trace the male lineage. Y markers are particularly useful in resolving DNA from different males, such as with sexual assault mixtures.