Unit of measure abbreviation
Keywords: unit of measure abbreviation
Description: (These abbreviations may be used without definition. They are not followed by periods. The same form is used in the plural.) The Journal recommends the use of the International System of Units
(These abbreviations may be used without definition. They are not followed by periods. The same form is used in the plural.)
The Journal recommends the use of the International System of Units (SI) (Page, C.H. and Vigoureux, P. Editors, NBS Special Publication 330, U.S. Government Printing Office; see also the IUPAC Manual of Symbols and Terminology for Physicochemical Quantities and Units (1979) Pergamon Press). However, it will continue to accept certain units as listed here (e.g. Ångstrom, calorie, minute) even though they are not part of the SI. Note that wavelength should be expressed in nanometers or in Ångstrom units; millimicron is specifically unacceptable.
a Terms such as milligram percent (mg%) should not be used. Weight concentrations should be given as g/ml, g/100 ml, etc.
b The letter M is not an abbreviation for mole; it is reserved for molar. Use m M for 10 -3 and µ M for 10 -6 M. Avoid designating concentrations as µmol per ml. The designation should, in this case, properly be m M (i.e. millimolar). Maintain consistency in the use of units in situations where they are to be compared (e.g. do not juxtapose 10 -4 M and 10 -5 M ).
c 1 becquerel = 1 disintegration per second or 60 dpm. 1 Ci = 3.7 x 10 10 Bq. Note: becquerel is the preferred term in the International System of Units (SI).
d Molecular mass (symbol m) is expressed in daltons (Da); one dalton is 1/12 of the mass of carbon 12. Molecular weight (M r. relative molecular mass) is the ratio of the mass of a molecule to 1/12 of the mass of carbon 12 and is dimensionless. Hence, it is not correct to express M r in daltons.
e For thermodynamic terms see the Recommendations of the Interunion Commission on Biothermodynamics ((1976) J. Biol. Chem. 251, 6879-6886 ).