Chapter 9: Biotechnology and DNA Technology

Biotechnology and DNA Technology explains the use of restriction enzymes—molecular scissors that cut DNA at specific sequences—to create recombinant DNA by combining genes from different organisms. The DNA fragments can then be inserted into vectors such as plasmids or viral genomes to propagate within host cells. Polymerase chain reaction (PCR) is introduced as a powerful method for amplifying DNA, with applications in disease diagnostics, forensics, and molecular biology. The chapter explains how DNA can be inserted into host cells through transformation, electroporation, gene guns, and protoplast fusion. It details the selection and screening process used to identify cells that have successfully incorporated foreign DNA, including the use of antibiotic resistance markers and blue-white screening. The chapter highlights how bacteria and other microbes are used to produce important products like insulin, growth hormones, and vaccines through genetic modification. Genetically modified organisms (GMOs), transgenic plants, and gene silencing techniques such as RNA interference (RNAi) are discussed in the context of agriculture, medicine, and environmental cleanup. The ethical and safety concerns of biotechnology, including issues around genetically modified food, bioterrorism, and gene therapy, are addressed to encourage responsible scientific practice. Throughout the chapter, techniques like DNA sequencing, microarrays, and genome editing tools are emphasized as expanding the possibilities of microbial research and medicine. This chapter equips students with an understanding of how microbial genetics underpins biotechnological innovations that are reshaping health care, agriculture, and environmental science.