A DNA construct is an artificially-designed segment of DNA borne on a vector that can be used to incorporate genetic material into a target tissue or cell.[1] A DNA construct contains a DNA insert, called a transgene, delivered via a transformation vector which allows the insert sequence to be replicated and/or expressed in the target cell. This gene can be cloned from a naturally occurring gene,[2] or synthetically constructed.[3] The vector can be delivered using physical, chemical or viral methods.[4] Typically, the vectors used in DNA constructs contain an origin of replication, a multiple cloning site, and a selectable marker.[2] Certain vectors can carry additional regulatory elements based on the expression system involved.[5]
DNA constructs can be as small as a few thousand base pairs (kbp) of DNA carrying a single gene, using vectors such as plasmids or bacteriophages, or as large as hundreds of kbp for large-scale genomic studies using an artificial chromosome.[2] A DNA construct may express wildtype protein, prevent the expression of certain genes by expressing competitors or inhibitors, or express mutant proteins, such as deletion mutations or missense mutations. DNA constructs are widely adapted in molecular biology research for techniques such as DNA sequencing, protein expression, and RNA studies.[5]