micromoles

Micromoles are a unit of amount of substance equal to one millionth of a mole. The symbol is µmol (also μmol or umol when the Greek letter is unavailable). A mole contains 6.02214076×10^23 entities, so one micromole corresponds to about 6.02214076×10^17 entities. The micro prefix denotes 10^-6, and the unit is used to express small quantities of a substance.

Conversions with related units are straightforward: 1 µmol equals 0.001 millimoles (mmol) and equals 1000 nanomoles (nmol). Conversely, 1 nmol equals 0.001 µmol and 1 mmol equals 1000 µmol. For solutions, the related concentration unit is micromolar (µM), meaning micromoles of solute per liter of solution. For example, a 5 µM solution contains 5 micromoles of solute per liter.

Micromoles are widely used in chemistry, biochemistry, molecular biology, and pharmacology to express small amounts of substances and to describe concentrations in experiments. They are particularly convenient when dealing with reagents, enzymes, nucleotides, and other biomolecules that are present or required in micromolar to nanomolar ranges.

In summary, a micromole is a small, standard unit of amount of substance equal to 10^-6 moles, commonly used together with its concentration counterpart, the micromolar, to quantify quantities of chemicals and biological materials.