| Abbreviation | Definition |
|---|---|
| NARL | National Analytical Reference Laboratory |
| NARL | National Atmospheric Research Laboratory |
| NARL | Naval Arctic Research Laboratory |
| NARL | Northern Appalachian Research Laboratory |
| NAS | Nucleus Accumbens Septum |
| NASBA | Nucleic Acid Sequence Based Amplification |
| NASL | Nutrient Analytical Services Laboratory |
| NAUF | No Added Urea Formaldehyde |
| NBCL | National Biological Control Laboratory |
| NBL | Nanoengineering and Biodesign Laboratory |
| NBL | Neutral Buoyancy Laboratory. |
| NBLT | National Botulism Laboratory Team |
| NBSCP | National Blood Supply Contingency Plan |
| NBT | Nitro- Blue Tetrazolium |
| NBU | Nonreplicating Bacteroides Unit |
| NCBB | Nebraska Community Blood Bank |
| NCCL | Neural Cardiovascular Control Laboratory |
| NCCLS | The National Committee for Clinical Laboratory Standards |
| NCDL | Northern California Diagnostic Laboratories |
| NCEL | Naval Civil Engineering Laboratory |