D

 As is explained in Commonwealth v. Curnin, 409 Mass. 218; 565 N.E.2d at 446-47, and U.S. v. Jakobetz, 955 F.2d at 792-93, RFLP analysis involves several steps. 

1. Extraction of DNA. The DNA must be extracted from the evidentiary sample by using chemical enzymes. An enzyme is then added to digest cellular material that is not DNA, thereby providing a purer sample. 

2. Restriction or Digestion. The DNA is then mixed with restriction enzymes which cut the DNA molecules into fragments at specific base sequences. The restriction enzymes recognize particular sequences of base pairs. The enzymes sever ...