What is the main purpose of using restriction enzymes in bioengineering?

Using restriction enzymes in bioengineering primarily serves the purpose of cleaving DNA at specific sequences, which is crucial for the creation of recombinant DNA. These enzymes act like molecular scissors that cut DNA strands at precise locations known as recognition sites. By doing this, scientists can isolate specific gene segments or modify existing genes, facilitating the insertion of these segments into vectors for cloning or into the genomes of various organisms. This process is foundational in many applications such as genetic engineering, where researchers want to alter the genetic makeup of organisms for purposes such as producing proteins, studying gene function, or developing new therapies.

The other options, though related to molecular biology and bioengineering, serve different functions. Amplifying DNA segments is typically achieved using techniques like polymerase chain reaction (PCR) rather than restriction enzymes. Measuring RNA levels is done via methods such as quantitative PCR or RNA sequencing, which assess gene expression rather than gene modification. Creating vaccines against viral infections often involves techniques like recombinant DNA technology, but it is a broader application than the specific action of restriction enzymes. Thus, the correct answer emphasizes the precise role of restriction enzymes in DNA manipulation and the foundational role they play in genetic engineering.