Both PCR and molecular cloning can be used to direct the replication of DNA sequences. There are several fundamental differences between these two methods.

• Molecular cloning replicates DNA within in a living cell, while PCR replicates DNA in an in vitro solution, free of living cells.
• Molecular cloning involves cutting and pasting the sequences, while PCR amplifies DNA by copying an existing sequence.
• DNA cloned by molecular cloning is usually faithfully copied and fully functional, whereas PCR introduces errors in sequence, resulting in mutations.