Renin, Direct Rapid Plasma Reagin (RPR) with Reflex to RPR Titer or T. pallidum Antibody by Particle Agglutination Reptilase Time with Reflex to Reptilase Time 1:1 Mix Rapid Plasma Reagin (RPR) with Reflex to Titer Respiratory Culture and Gram Stain Rett Syndrome (MECP2), Deletion and Duplication Rickettsia typhi (Typhus Fever) Antibodies, IgG & IgM by IFA Rett Syndrome (MECP2), Full Gene Sequencing Rickettsia typhi (Typhus Fever) Antibody, IgG by IFA Rett Syndrome (MECP2), Sequencing and Deletion/Duplication Rickettsia typhi (Typhus Fever) Antibody, IgM by IFA Rh Type Only Risk of Ovarian Malignancy Algorithm RhCc Antigen (RHCE) Genotyping Risperidone and Metabolite, Serum or Plasma Respiratory Viruses DFA with Reflex to Viral Culture, Respiratory RhD Antigen (RhD) Genotyping Ristocetin-Induced Platelet Aggregation Respiratory Viruses Rapid Culture RhEe Antigen (RHCE) Genotyping