What technique is used to produce millions of copies of a DNA sequence without using bacteria to amplify the DNA?

The technique used to produce millions of copies of a DNA sequence without relying on bacteria for amplification is Polymerase Chain Reaction (PCR). PCR is a molecular biology method that allows for the exponential amplification of a specific DNA segment.

The process involves repeated cycles of denaturation, annealing, and extension. During the denaturation step, the double-stranded DNA is heated to separate it into two individual strands. Then, during the annealing phase, short DNA primers bind to the specific target sequences on the single-stranded DNA. Finally, in the extension phase, a DNA polymerase enzyme synthesizes new DNA strands by extending from the primers, creating duplicate copies of the target sequence.

This method is highly efficient and sensitive, allowing for the amplification of very small amounts of DNA in a relatively short time. PCR is widely utilized in various applications such as cloning, gene expression analysis, genetic mapping, and diagnostics.

In contrast, gene cloning typically involves inserting a DNA fragment into a vector and introducing it into bacteria, which then replicate the DNA. Hybridization is a process where two complementary DNA strands pair, and restriction enzyme analysis involves cutting DNA into fragments for studying the sequences. These methods do not provide the rapid amplification capability that PCR offers, making PCR the suitable