The document discusses recombinant DNA technology. It begins by defining recombinant DNA as DNA molecules formed by joining DNA from two different species. It then discusses the key steps in recombinant DNA technology, including isolating DNA, cutting DNA with restriction enzymes, joining DNA together with DNA ligase, and amplifying the recombinant DNA by inserting it into a host cell. The document also covers applications of recombinant DNA technology such as producing insulin, vaccines, and monoclonal antibodies.