Ready reference guides

[Zipporah Schumaker]

In the US, most laboratory test results are reported in what are termed conventional units; the rest of the world reports results in Système International d’Unités (SI) or international units (IU). The unit basis for SI is updated periodically by a panel.
Many SI units are the same as units used in the US system; however, SI units for concentrations are not. SI concentrations are reported as moles (mol) or decimal fractions of a mole (eg, millimole, micromole) per unit volume in liters (L). Conventional units are reported as mass (eg, grams, milligrams) or chemical equivalency (eg, milliequivalents) per unit volume, which may be in liters or decimal fractions of liters (eg, deciliters, milliliters). Results reported in amount per 100 mL (1 dL) are sometimes expressed as percent (eg, 10 mg/dL may be written as 10 mg%).
Moles, milligrams, and milliequivalents: A mole is an Avogadro’s number (6.023