| R R R R R | letter |
| Radiation, ionizing | chapter 12 | micro 509 | heading |
| Radiation, ultraviolet | chapter 12 | micro 509 | heading |
| Receptor, viral | chapter 10 | micro 509 | heading |
| Recipient cell | chapter 8 | micro 509 | heading |
| Recombinant DNA and Genetic Engineering | chapter 8 | micro 509 | chapter title |
| Recombinant DNA technology | chapter 8 | micro 509 | heading |
| Recombinant vaccine | chapter 17 | micro 509 | heading |
| Redi, Francesco | chapter 1 | micro 509 | heading |
| Reduction | chapter 2 | micro 509 | heading |
| Reduction | chapter 5 | micro 509 | heading |
| Refraction | chapter 3 | micro 509 | heading |
| Refraction, index of | chapter 3 | micro 509 | heading |
| Refrigeration | chapter 12 | micro 509 | heading |
| Regeneration of NAD+ | chapter 5 | micro 509 | heading |
| Reistance to antibiotics, chromosomal | chapter 13 | micro 509 | heading |
| Reistance to antibiotics, mutation-mediated | chapter 13 | micro 509 | heading |
| Release (virus) | chapter 10 | micro 509 | heading |
| Replication | chapter 10 | micro 509 | heading |
| Replication of T4 phage | chapter 10 | micro 509 | heading |
| Replication, virus | chapter 10 | micro 509 | heading |
| Requirements, oxygen | chapter 6 | micro 509 | heading |
| Reservoir hosts | chapter 11 | micro 509 | heading |
| Reservoirs of infection | chapter 15 | micro 509 | heading |
| Resident microflora | chapter 14 | micro 509 | heading |
| Resistance plasmids | chapter 8 | micro 509 | heading |
| Resistance to antibiotics | chapter 13 | micro 509 | heading |
| Resistance to antibiotics, acquired | chapter 13 | micro 509 | heading |
| Resistance to antibiotics, extrachromosomal | chapter 13 | micro 509 | heading |
| Resolution | chapter 3 | micro 509 | heading |
| Respiration, aerobic | chapter 5 | micro 509 | heading |
| Respiration, cellular | chapter 5 | micro 509 | heading |
| Response, primary | chapter 17 | micro 509 | heading |
| Response, secondary | chapter 17 | micro 509 | heading |
| Restriction endonuclease | chapter 8 | micro 509 | heading |
| Ribosomes | chapter 4 | micro 509 | heading |
| Rickettsia (bacteria) | chapter 9 | micro 509 | heading |
| Rickettsia prowazekii (wave) | supplement | micro 509 | wave |
| Rickettsia rickettsii | chapter 9 | micro 509 | heading |
| Rickettsia rickettsii (wave) | supplement | micro 509 | wave |
| RNA sequencing | chapter 9 | micro 509 | heading |
| RNA viruses, single-stranded | chapter 10 | micro 509 | heading |
| Rods, anaerobic, Gram-negative (bacteria) | chapter 9 | micro 509 | heading |
| Rods, facultatively anaerobic, Gram-negative (bacteria) | chapter 9 | micro 509 | heading |
| Roundworms | chapter 11 | micro 509 | heading |
| Routinely administered vaccines | chapter 17 | micro 509 | heading |