19.1.1—Recombinant DNA definition

Recombinant DNA is DNA made by combining nucleotide sequences from two or more different sources. The universal genetic code makes it possible for a sequence from one organism to be read in another organism, although the code itself does not guarantee successful expression.

1. Select DNA sequences from the sources that provide the required information.
2. Combine the sequences into one DNA construct; the construct is recombinant DNA.
3. If the construct is introduced into a host cell, it may be copied and/or expressed there when the host has the required cellular control.
4. A host containing introduced genetic material is a genetically modified organism (GMO); if the introduced sequence came from another species, it is also described as transgenic.

Shared codon meanings allow genetic information to be transferred between species: a host can potentially use the transferred sequence to make the same type of polypeptide. Recombinant DNA is therefore the altered DNA construct, not the whole organism and not automatically a useful product.

Keep the levels separate: recombinant DNA describes the DNA molecule or construct; transgenic describes introduced DNA from another species; GMO describes an organism with introduced genetic material. This card establishes the concept and its expression/replication boundary only. Restriction enzymes, vectors, promoters, PCR, gel analysis, applications and risk evaluation are later learning jobs.