UK gills
UK gills are volume measurements for liquids in the United Kingdom. One UK gill is equivalent to a quarter of a UK pint (about 142 milliliters).
Microliters
Microliters are a unit of volume in the metric system used to measure very small amounts of liquid. One microliter is equal to one millionth of a liter. This tiny unit of measurement is often denoted by the symbol μL. To put it into perspective, a single drop of water is roughly equivalent to about 50 microliters.