| OEF | oil immersion field; oxygen extraction fraction |
|---|---|
| OF | occipitofrontal; open field [test]; optical fundus; orbitofrontal; osmotic fragility; osteitis fibro... |
| OFAGE | orthogonal field alternation gel electrophoresis |
| OIF | observed intrinsic frequency; oil immersion field; Osteogenesis Imperfecta Foundation |
| PFGE | pulsed field gel electrophoresis |