zeptoliters

Zeptoliters (symbol zL) are a unit of volume in the SI system equal to 10^-21 liters, i.e., one sextillionth of a liter. Because 1 liter equals 0.001 cubic meters, 1 zeptoliter is 1×10^-24 cubic meters. Geometrically, 1 zL corresponds to the volume of a cube roughly 10 nanometers on each side.

The zepto- prefix denotes 10^-21 and sits among the SI prefixes for submultiples of liters, between atto- (10^-18) and yocto- (10^-24). The zeptoliter is a non-SI unit that is accepted for use with the SI and is mainly encountered in discussions of nanoscale volumes, microfluidics, and other contexts involving extremely small fluid quantities.

In practical terms, zeptoliters are rarely used in everyday laboratory work; smaller units such as nanoliters or attoliters are more common in microfluidics and molecular biology, while yoctoliters may appear only in highly theoretical or specialized measurements. Conversions: 1 zL = 10^-21 L = 10^-24 m^3. This scale helps convey the smallness of certain nanoscale volumes and provides a precise reference point within the broader system of SI prefixes.

See also: SI prefixes, liters, cubic meter, nanoliter, attoliter, yoctoliter.