A DNA construct is an artificially constructed segment of nucleic acid that is going to be "transplanted" into a target tissue or cell. It often contains a DNA insert, which contains the gene sequence encoding a protein of interest, that has been subcloned into a vector, which contains bacterial resistance genes for growth in bacteria, and promoters for expression in the organism. 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. A DNA construct is often used in molecular biology to analyze macromolecules such as proteins or RNA in more detail.