In research style reports, always use the appropriate symbol for SI units.
Always use a non-breaking space between the number and its unit e.g. 24 °C
Example: ml (or mL) rather than milliliters
Here are some common SI units and associated symbols.
| unit | Symbol |
|---|---|
| microliter | µl (or µL) |
| milliliter | ml (or mL) |
| liter | l (or L) |
| unit | Symbol |
|---|---|
| gram | g |
| milligram | mg |
| microgram | µg |
| unit | Symbol |
|---|---|
| micromolar | µM |
| millimolar | mM |
| molar | M |
| percent weight/volume | % (w/v) |
| percent volume/volume | % (v/v) |
| unit | Symbol |
|---|---|
| minute | min |
| second | s |
| hour | h |
| day | d |
Do not add capitols or periods to the symbols unless they are at the beginning or end of a sentence respectively.
Always place a leading 0 in front of numbers less than 1.
0.5 NOT .5
In scientific reports we use numerals rather than words for all quantitative expressions. This emphasizes the quantitative value of what we are presenting (and also saves space).
75 bp (base pairs)
13 plants
0.8 mm
If a sentence begins with a number you must spell it out (or better yet, reword the sentence so it does not start with a number).
In qualitative or unitless instances, spell out the words for zero and for numbers one to ten. Do not use numeral in this case. For example: When 1 g of sample was used, there were two possible outcomes.
If two numbers are adjacent, for clarification spell out one of the numbers (or better yet, reword the sentence so that two numbers are not adjacent). When choosing which number to spell out, keep any numbers associated with units (e.g. 5 g) as numerals. We placed five 0.5 mL aliqouts of buffer in each of five 1.5 mL microcentrifuge tubes.