Convert Stone (US) (st (US)) to Picogram (pg) instantly.
About these units
Stone (US) (st (US))
The US stone was an informal and nonstandardized unit occasionally used in the 19th century, with no single agreed-upon value. Unlike the British stone (14 pounds), the US stone varied regionally and by trade context, typically ranging from 12 to 16 pounds, depending on the commodity and location. Farmers, butchers, and merchants sometimes used stones to weigh produce, meat, or livestock, but the lack of uniform regulation prevented it from becoming an official or widely adopted unit. Today, the US stone is entirely obsolete, but references to it appear in historical American trade documents, agricultural records, and pre-standardization weight systems. It serves as a reminder of the diversity of early American measurements before the widespread adoption of the avoirdupois pound.
Picogram (pg)
A picogram, or 10⁻¹² grams, is widely used in molecular biology, biochemistry, and medicine. Hormones, signaling molecules, and certain viruses fall within the picogram mass range. Laboratories often quantify DNA or RNA using picograms, especially in single-cell analysis. Cellular processes frequently involve minuscule quantities of molecules, so picogram measurements allow researchers to study gene expression, protein synthesis, and chemical reactions with extreme accuracy. Diagnostic tests—such as those for biomarkers in blood—often require detection at picogram per milliliter concentrations. The picogram is a crucial bridge between the molecular scale and measurable laboratory practice, enabling breakthroughs in medical diagnostics and biotechnology.