Mikromolar

Mikromolar is a term used in chemistry and biochemistry to denote a concentration equal to one micromole of solute per liter of solution. The standard term in English is micromolar, abbreviated μM, while in some languages, such as German, the form Mikromolar is common and capitalized as a noun.

Definition and notation: 1 μM equals 1 × 10^-6 moles per liter (mol/L). It is a unit of molarity and is not a unit of mass. In laboratory practice, μM is used to describe the concentrations of reagents, substrates, inhibitors, and signaling molecules in assays, reactions, and cell-based experiments.

Applications and typical use: Micromolar concentrations are widespread in biochemistry, pharmacology, enzymology, and molecular biology. They are appropriate for many enzyme kinetics studies, ligand-binding assays, and cellular signaling experiments, where activities often occur in the low- to mid-micromolar range. Depending on the system, working concentrations may span from tens of nanomolar to several micromolar.

Measurement and conversions: Concentrations are expressed in molarity (mol/L). Practical conversions include: 1 μM = 1 × 10^-6 mol/L, 1 mM = 1 × 10^-3 mol/L, 1 nM = 1 × 10^-9 mol/L. Preparing μM solutions usually involves serial dilutions from higher-concentration stock solutions. In terms of particle count, 1 μM corresponds to roughly 6.02 × 10^17 molecules of solute per liter (Avogadro’s number times the molarity), assuming a single solute species.