Semiconservative replication describes the mechanism by which DNA is replicated in all known cells. This mechanism of replication was one of three models originally proposed for DNA replication:

• Semiconservative replication would produce two copies that each contained one of the original strands and one new strand.
• Conservative replication would leave the two original template DNA strands together in a double helix and would produce a copy composed of two new strands containing all of the new DNA base pairs.
• Dispersive replication would produce two copies of the DNA, both containing distinct regions of DNA composed of either both original strands or both new strands.