PNA-Mediated PCR Clamping: Applications and Methods

About 90% of sequence variants in humans are differences in single bases of DNA, called single nucleotide polymorphisms (SNPs). When two individuals are compared, their genomic DNA differs at ∼1/1000 nucleotides (1). Neutral polymorphisms may be responsible for subtle differences between individuals, such as hair and eye color, or may be silent identifiers of variability and relatedness. Other polymorphisms cause genetic diseases such as hemophilia and are referred to as mutations. Polymorphisms within an individual may cause cancer or other diseases, are responsible for the variability of our immune response, and have been implicated in the aging process. Identification of polymorphisms can therefore be useful in diagnosis of genetic disease, detection of tumors, study of immune response and aging, identification of microbial strains, and developing relatedness trees between humans or other organisms.