| SPF | skin protection factor; specific-pathogen free; spectrophotofluorometer; S-phase fraction; split pro... |
|---|---|
| SUN | standard unit of nomenclature; serum urea nitrogen |
| BDC | Bazex-Dupre-Christol [syndrome]; burn-dressing change |
| BI | background interval; bacterial or bactericidal index; base-in [prism]; basilar impression; Billroth ... |
| BU | base of prism up; Bethesda unit; blood urea; Bodansky unit; bromouracil; burn unit |