The copy of DNA that is used to direct the synthesis of a specific protein is called messenger RNA (mRNA).

Here's a breakdown:

* DNA contains the genetic code for all proteins in an organism.

* Transcription: DNA is copied into mRNA, which is a single-stranded molecule. This occurs in the nucleus of a cell.

* Translation: The mRNA molecule travels out of the nucleus and into the cytoplasm, where it binds to ribosomes. Ribosomes use the mRNA code to assemble amino acids into a specific protein.

So, mRNA is the intermediary molecule that carries the genetic information from DNA to the ribosomes, where it is translated into protein.