Which technique is primarily used to amplify small quantities of DNA for analysis?

The technique primarily used to amplify small quantities of DNA for analysis is the Polymerase Chain Reaction (PCR). PCR enables researchers to produce millions of copies of a specific DNA segment from a tiny initial amount. This amplification is crucial because it allows for sufficient quantities of DNA to be obtained for detection, analysis, and various applications such as genetic testing, forensic analysis, and research.

PCR works through a series of temperature changes that facilitate the denaturation of DNA strands, annealing of primers to target sequences, and extension by a DNA polymerase enzyme. This cycle is repeated multiple times, exponentially increasing the amount of DNA available for subsequent procedures like gel electrophoresis, where it can be separated and analyzed.

Other options, such as gel electrophoresis, DNA sequencing, and cloning, do not serve the primary purpose of amplifying DNA directly. Gel electrophoresis is a method used to separate DNA fragments based on size but does not amplify them. DNA sequencing determines the order of nucleotides but assumes that adequate DNA is available for such analysis. Cloning involves creating copies of an entire organism or cell line, which is not specifically about amplifying a limited DNA sample for analytical purposes. Thus, PCR stands out as the key technique for amplifying DNA quickly