What Is an Attomole (amol)? Definition, Conversion, Uses & Examples
The attomole (symbol: amol) is a decimal fraction of the mole and is equal to 10−18 mol. It measures the amount of substance rather than mass or volume. The mole is the SI base unit for amount of substance, while the attomole is one of its standard metric multiples created by applying the SI prefix atto-.
Scientists use attomoles when working with samples that contain extremely small numbers of molecules but are still large enough to be quantified by advanced analytical instruments. The unit is especially useful in nanotechnology, molecular diagnostics, pharmaceutical development, environmental chemistry, and biomedical research, where trace concentrations must be measured accurately.
History and Origin
The attomole was introduced through the International System of Units (SI) by combining the SI prefix atto- (10−18) with the mole. The mole became an SI base unit in 1971 and was redefined in 2019 using the fixed numerical value of the Avogadro constant, making all SI-prefixed units—including the attomole—derive directly from this exact definition.
Where Is Attomole Used?
Although not commonly encountered in everyday life, the attomole is widely used in scientific research and high-precision laboratories. Typical applications include:
- DNA and RNA quantification
- Protein and peptide analysis
- Mass spectrometry
- Clinical diagnostics
- Nanotechnology research
- Analytical and pharmaceutical chemistry
- Environmental trace analysis
Relationship to Other Amount of Substance Units
- 1 attomole = 10−18 mole
- 1 femtomole = 1,000 attomoles
- 1 picomole = 1,000,000 attomoles
- 1 nanomole = 1,000,000,000 attomoles
- 1 micromole = 1,000,000,000,000 attomoles
- 1 millimole = 1,000,000,000,000,000 attomoles
Explore related conversions:
- Attomole to Mole
- Mole to Attomole
- Attomole to Femtomole
- Attomole to Picomole
- Attomole to Nanomole
- Attomole to Micromole
Real-World Example
Modern analytical instruments can detect substances at the attomole level. For example, researchers studying biomarkers or genetic material may measure only a few attomoles of DNA or proteins in a biological sample. Expressing these quantities in attomoles provides a convenient way to report very small amounts while maintaining compatibility with the SI system.
Frequently Asked Questions
What is an attomole?
An attomole is an SI-prefixed unit of amount of substance equal to 10−18 mole.
What is the symbol for attomole?
The standard SI symbol for attomole is amol.
How many attomoles are in one mole?
One mole equals 1018 attomoles.
Where are attomoles commonly used?
Attomoles are primarily used in analytical chemistry, molecular biology, pharmaceutical research, nanotechnology, and clinical laboratories.
Is attomole an SI unit?
Yes. The attomole is an SI-prefixed decimal multiple of the mole, which is the SI base unit for amount of substance.