|Look up micro- in Wiktionary, the free dictionary.|
- The size of the influenza virus is about 0.8 to 1.2 micrometres.
- Typical bacteria are 1 to 10 micrometres in diameter. Eukaryotic cells are typically 10 to 100 micrometres in diameter. 
- The metric system was introduced in 1795 with several metric prefixes, of which, however, only six were adopted as SI prefixes by the 11th CGPM conference in 1960, whereas myria (104) as well as double and demi were not adopted. In 1873, micro and mega were recommended by the British Association for the Advancement of Science. The other dates relate to recognition by a resolution of the CGPM.
Symbol encoding in character sets
The official symbol for the SI prefix micro- is a Greek lowercase mu (μ). For reasons stemming from its design, there are two different characters in Unicode, which appear slightly different in some fonts, although most fonts use the same glyph. The micro sign (µ) is encoded in the "Latin-1 Supplement" range identical to ISO/IEC 8859-1 (since 1985), at
U+00B5 (Alt+0181)(Unicode 1.0, 1991). The Greek letter (μ) is encoded in the Greek range at
U+03BC (Alt+956). According to The Unicode Consortium, the Greek letter character is preferred, but implementations must recognize the micro sign as well.
Other abbreviating conventions
In some health care institutions, house rules deprecate the standard symbol for microgram, "μg", in prescribing or chart recording, because of the risk of misdose via the misreading of poor handwriting. The two alternatives are to abbreviate as "mcg" or to write out "microgram" in full (see also List of abbreviations used in medical prescriptions). But this deprecation, focused on bedside misdose avoidance in contexts where handwriting is often present, does not extend to all health-care contexts and institutions (for example, some clinical laboratories' reports adhere to it, whereas others don't), and in physical sciences academia, "μg" remains the sole official abbreviation.
- International Bureau of Weights and Measures (2006), The International System of Units (SI) (PDF) (8th ed.), ISBN 92-822-2213-6
- Biology by Campbell & Reece tenth edition page 98 Ch. 6 A Tour of the Cell
- Prefixes of the International System of Units, International Bureau of Weights and Measures (page visited on 9 May 2016).
- Unicode Technical Report #25
- ISO 2955, Table 2.
- Burtis, Carl A.; Ashwood, Edward R.; Bruns, David E. (2012), Tietz Textbook of Clinical Chemistry and Molecular Diagnostics (5th ed.).