milligram: one thousandth (1/1,000) gram
unit of measurement: any division of quantity accepted as a standard of measurement or exchange
gram's method: a staining technique used to classify bacteria; bacteria are stained with gentian violet and then treated with Gram's solution; after being decolorized with alcohol and treated with safranine and washed in water, those that retain the gentian violet are Gram-positive and those that do not retain it are Gram-negative