> See also: > - [[DNA Replication]] > - [[Restriction Enzymes]] > - [[Cloning and Expression Vectors]] # Recombinant DNA Technology Creation of **recombinant DNA** involves combining sequences that aren’t normally found together (e.g. human + bacterial DNA), and is the primary tool for the **genetic engineering** of organisms **Plasmids** are circular pieces of double stranded DNA (dsDNA) that naturally occur in bacterial cells. The significantly smaller size of plasmids compared the eukaryotic chromosomes makes them easier to edit/manipulate. Plasmids also lack any condensed state ### DNA Ligation > See also > - [[Nucleic Acids]] It’s important to remember that *the bonds between two strands of DNA are not covalent*. They are primarily held together by *hydrogen bonds* (a type of [[Intermolecular Forces|intermolecular force]]) between *complementary nucleotides*. Special enzymes such as **DNA Ligase** are able to covalently join two separate strands together by creating a *phosphodiester* bond between the *3’ hydroxyl group* of one strand and the *5’ phosphate group* of another. - These are often ATP dependent reactions. Many buffers used in ligation protocols will contain ATP to compensate. Without a ligating agent, the complementary sticky ends would simply [[DNA Hybridization|hybridize]] together rather than become permanently integrated into the strand. ## Methods of Genetic Engineering > See also: > - [[CRISPR]] ### Site-Specific Recombinase > See also: > - [[Cre-Lox Recombination]] - [ ] Recombinase enzymes ### Site-Specific Recombinase > See also: > - [[Cre-Lox Recombination]] - [ ] Recombinase enzymes ### Viral Vectors - Lentivirus - Retrovirus