DNA is cloned from DNA
While DNA is not alive, it is a large macromolecule, which provides itself the instructions for self-replication. The DNA-replicating enzymes found in a living cell will faithfully read the nucleotide sequence in an existing DNA molecule and make a copy, resulting in two DNA molecules. The two molecules will each consist of one 'old' strand template and one 'new' strand of complementary nucleotides. Gene cloning in the laboratory takes advantage of the accuracy of DNA replicating enzymes and the conserved nature of the replication process. Genes that originated from any source can be cloned by using the DNA replication system in a living bacteria or yeast cell or the potential for replicating enzymes to perform their function in a test tube in a process called PCR. We have described PCR in another lesson. We will examine cloning with bacteria in this lesson. First, lets take a look at what a gene is.