| Abbreviation | Definition |
|---|---|
| NVSL | National Veterinary Services Laboratories |
| NWABR | Northwest Association for Biomedical Research |
| NWDL | Northeast Wildlife DNA Laboratory |
| NWSS | National Wastewater Surveillance System |
| NYD | Not Yet Determined |
| O | Outcomes |
| O&P | Ova and Parasites |
| OAL | Organic Analytical Laboratory |
| OB | Occult Blood |
| OBL | Outpatient Based Laboratory |
| OBSL | Optical Bio Sensing Laboratory |
| OCD | Osteochondritis Dissecans |
| OCHS | Ontario Child Health Study |
| OCL | Ocean Climate Laboratory |
| OCMB | Ocular Cell And Molecular Biology |
| OCMB | Ocular Cell Molecular Biology |
| OCP | Ortho-CresolPhthalein |
| OCP | Ova, Cysts Parasites |
| OCP | Ova, Cysts & Parasites |
| OCT | Oxytocin Challenge Test |