Phosphate Buffer

**Semantic type:** Indicator, Reagent, or Diagnostic Aid

**Definition:** A chemical reagent containing at least any one of the many phosphoric acid derivatives, usually in salt form. The phosphoric salt may be one of three types: strongly acid monometallic, neutral or mildly alkaline dimetallic, and strongly alkaline tri-metallic. Phosphate buffers are typically adjusted to maintain a certain pH or are "buffered" with other chemical compounds. Phosphate reagents are used in research laboratories, medicine or industry in various technical procedures. (NCI04)