ABSTRACT
Amplification techniques can be classified into two types, namely thermal cycling, where temperature of the reaction varies [polymerase chain reaction (PCR) and ligase chain reaction], and isothermal cycling in which temperature of the reaction remains constant [nucleic acid sequence-based amplification and branched DNA technology]. PCR involves a series of cycles of three successive reactions. The product of the DNA acts as a template strand for further DNA synthesis. Primers are short nucleotide sequences, which can bind to the target DNA. So prior knowledge of the DNA sequence (to be amplified) is mandatory. PCR methods based on mitochondrial genes have been used in forensic science because of their high copy number per cell and lack of recombination. DNA profiling (DNA typing, genetic fingerprinting, DNA testing) is a technique used in forensic science to identify criminals based on their DNA profile. PCR is widely used for the DNA analysis of archaeological specimens.
