Random Man: A theoretical man of unknown genetic comparison from a population with the same racial background as the alleged father.

Random Man Not Excluded (RMNE): The frequency with which men selected at random from the same racial group as the alleged father and tested to the same extent as the alleged father would not be excluded as the biological father of the child.

Recessive: A trait that is partially or completely masked by the effect of a dominant allele. The dominant A or B allele masks the presence of the recessive O allele.

Red Cell Antigens: Genetic markers found on the surface of red cells, e.g. ABO, Rh, MNSs.

Replication: The enzymatic process of making new DNA based on the use of use of an existing strand of DNA as a template. The enzymes that perform this process require a primer, a short piece of DNA complementary to the template that defines the base at which the replication will start and that will become part of the newly synthesized DNA.restriction enzymes (RE), restriction endonucleases. A class of enzymes obtained from microorganisms that cut the DNA strands at specific four to twelve base pair sequences. There are over one hundred restriction enzymes commercially available each having a different recognition site. In forensic science the most commonly used RE is called Hae III although there are some labs who still use Hinf I or Pst I.
Restriction Enzyme: A bacterial enzyme which recognizes a specific set of bases and the DNA at that specific site.

Restriction Fragment: A piece of DNA identified by a specific restriction enzyme.

Restriction Fragment Length Polymorphism (RFLP): Variations in the length of a DNA restriction fragment caused by the presence of a polymorphic locus within the fragment. Analysis of RFLPs by the Southern blotting method is the most common and definitive forensic DNA test.

RE Test Gel: A gel used to analyze DNA that has been cut by a restriction enzyme (RE) to ensure that the cutting of the DNA has been complete. Sometimes contaminants in forensic samples will inhibit the action of the enzyme and prevent it from cutting the DNA.

RNA Ribonucleic Acid: A nucleic acid polymer similar to DNA and used to translate the genetic code into a form useful by the cells.