1 Used other than as an idiom: see outer ,â core. ( 2 planetology) The hot liquid material found near the centre of some planets, distinct from the solid inner core. ( 3 geology) The part of the Earth between the mantle and inner core, responsible for generating the planet's magnetic field. 4  Link/Cite.
Differential Staining is a staining process which uses more than one chemical stain. Using multiple stains can better differentiate between different microorganisms or structures/cellular components of a single organism.
A basic stain stains the bacteria (the stain is a positively charged molecule that attaches to cells which are negatively charged or to negatively charged molecules in cells.) A negative stain does not stain cells (why its called a negative stain), it stains the background around the cells.