| Abbreviation | Definition |
|---|---|
| NI | Not Identified |
| NIAID | National Institute of Allergy and Infectious Diseases |
| NICD | National Institute of Common Diseases |
| NICE | National Institute Of Clinical Examiners |
| NICL | National Ice Core Laboratory |
| NIGL | NERC Isotope Geosciences Laboratories |
| NIHROC | National Institutes of Health Research Operations Center |
| NILA | National Independent Laboratory Association |
| NIMLT | National Institute of Medical Laboratory Technology |
| NIMP | Nogo Interacting Mitochondrial Protein |
| NINA | Neither Inactivation Nor Afterpotential |
| NIRL | National Immunohematology Reference Laboratory |
| NIRL | Neonatal Immunological Research Laboratory |
| NIRL | Neuromuscular Imaging Research Laboratory |
| NIRL | Neuromuscular Immunopathology Research Laboratory |
| NJAL | New Jersey Analytical Laboratories |
| NL | Neil Laboratories |
| NLAC | National Laboratory Animal Center |
| NLAC | National Laboratory of Animal Centre |
| NLAC | Network of Laboratory Animal Coordinators |