Which technique is specifically utilized for amplifying DNA sequences?

The technique utilized specifically for amplifying DNA sequences is polymerase chain reaction (PCR). PCR is a powerful method that allows researchers to create millions of copies of a specific DNA segment in just a few hours. This amplification is vital for various applications, including genetic testing, forensic analysis, and research in molecular biology.

PCR works by utilizing a series of temperature changes to denature the DNA strands, anneal primers specific to the target sequence, and extend the new DNA strands through the action of DNA polymerase. This cycle is repeated multiple times, leading to exponential amplification of the target DNA.

The other techniques listed do not focus on amplifying DNA. Western blot is used to detect specific proteins in a sample, SDS-PAGE separates proteins based on their size, and affinity chromatography is a method for purifying biomolecules based on their specific interactions. Each of these methods serves distinct purposes in molecular biology and biochemistry but does not involve the amplification of DNA as PCR does.